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Search Results (416814 CVEs found)
| CVE | Vendors | Products | Updated | CVSS v3.1 |
|---|---|---|---|---|
| CVE-2026-10133 | 1 Totolink | 1 X2000r | 2026-10-23 | 9.1 Critical |
| A stack-based buffer overflow vulnerability exists in the batchupg functionality of X2000R (version(s): TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327). A specially crafted HTTP request can lead to arbitrary code execution. An attacker can make an authenticated HTTP request to trigger this vulnerability. | ||||
| CVE-2026-10132 | 1 Totolink | 1 X2000r | 2026-10-23 | 9.1 Critical |
| A stack-based buffer overflow vulnerability exists in the boa formIpQos mac functionality of X2000R (version(s): TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327). A specially crafted HTTP request can lead to arbitrary code execution. An attacker can make an authenticated HTTP request to trigger this vulnerability. | ||||
| CVE-2026-10131 | 1 Totolink | 1 X2000r | 2026-10-23 | 9.1 Critical |
| An OS command injection vulnerability exists in the boa formPasswordSetup functionality of X2000R (version(s): TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327). A specially crafted HTTP request can lead to arbitrary code execution. An attacker can make an authenticated HTTP request to trigger this vulnerability. | ||||
| CVE-2026-105933 | 1 Apache | 1 Pulsar | 2026-10-23 | N/A |
| Apache Pulsar allows an administrator to require end-to-end message encryption for all topics in a namespace by setting the encryption_required namespace policy. When this policy is set, the broker rejects messages that are published without encryption. When the broker loads a persistent topic, it reads the namespace policies and the topic-level policies as part of topic initialization. If a step of this initialization fails, for example because of an error reading from the metadata store, a failure loading the topic-level policies or a failure in a later initialization step, the broker logs a warning, disables the encryption requirement for that topic, and completes the topic load as if it had succeeded. The topic is then served with encryption_required not enforced, even though the namespace policy requires it. Topic-level policies that could not be loaded are also not applied. While the encryption requirement is not enforced, an authenticated client with permission to produce to the affected topic can publish messages that are not encrypted, and the broker accepts and stores them. This applies both to producers created after the topic was loaded and to producers that were already connected. Messages published with encryption remain encrypted; the issue does not expose the content of encrypted messages or the encryption keys. The condition is not limited to transient failures. If the cause of the initialization failure persists, the encryption requirement is disabled again each time the topic is loaded, for example after a topic unload, a namespace bundle reassignment or a broker restart. An update to the namespace policies restores enforcement on a loaded topic, but only until the topic is loaded again. Enforcement is reliably restored only once the underlying cause of the failure has been resolved and the topic has been loaded again. The broker logs a warning when the encryption requirement is disabled, but the topic load is reported as successful and the state of the encryption requirement is not shown in the topic statistics. In fixed versions, a failure during topic initialization causes the topic load to fail so that it can be retried, instead of loading the topic with the encryption requirement disabled. This issue affects Apache Pulsar versions from 1.22.0-incubating before 4.0.14 and from 4.1.0 before 4.2.5. - 4.0.x version users should upgrade to at least 4.0.14. - 4.1.x and 4.2.x version users should upgrade to at least 4.2.5. Users operating versions prior to those listed above should upgrade to the aforementioned patched versions or newer versions. The currently supported Apache Pulsar release lines are 4.0.x and 5.0.x. The supported versions schedule is available at https://pulsar.apache.org/contribute/release-policy/. Users who rely on encryption_required and cannot upgrade immediately can monitor the broker logs for warnings containing "isEncryptionRequired will be set to false" (the exact wording of the message differs between releases), resolve the underlying cause of the failure, and then reload the affected topic and confirm that the warning does not recur. | ||||
| CVE-2026-105932 | 1 Apache | 1 Pulsar | 2026-10-23 | N/A |
| The Apache Pulsar broker admin REST API provides endpoints to read, set and remove the topic-level entry filter policy of a topic. For persistent topics these endpoints check that the caller is authorized for the entry filters topic policy operation. The corresponding endpoints for non-persistent topics (/admin/v2/non-persistent/{tenant}/{namespace}/{topic}/entryFilters) do not perform this authorization check. The only authorization check these endpoints perform is an indirect lookup permission check, made while the topic's partition metadata is retrieved; it is present in all affected versions. As a result, when authentication and authorization are enabled, an authenticated user who has been granted produce or consume permission on a non-persistent topic, or on its namespace, but not permission to manage the topic's policies can read, replace or remove the topic-level entry filter policy of that topic. These operations should be restricted to users with the tenant admin role or the superuser role. This impact analysis assumes that Pulsar has been configured with the default authorization provider. For custom authorization providers, the impact could be slightly different. The practical impact is limited by two broker configuration requirements, neither of which is met by default: - Entry filters must have been installed by the operator. Entry filter implementations are loaded only at broker startup from the broker's entry filters directory, which is empty by default. A request can only select among entry filters the operator has already deployed; setting any other filter name is rejected. The issue does not allow a caller to install or load entry filter code or to run arbitrary code in the broker. - Topic-level entry filter policies must be allowed to override the broker-level configuration (allowOverrideEntryFilters, which is disabled by default). When this setting is disabled, the topic-level entry filter policy has no effect on message dispatch. In deployments where both conditions are met, an unauthorized user can remove the topic-level entry filter policy of a non-persistent topic, for example one used to restrict which messages are delivered to consumers, or apply a different installed entry filter that withholds messages from subscriptions of that topic. Removing it makes the topic fall back to the namespace-level or broker-level entry filters, which are not removed. A changed policy affects only subscription dispatchers created after the change, for example for new subscriptions or when a subscription is re-created after all of its consumers have disconnected; dispatchers that already exist keep the entry filters they were created with. Because non-persistent topics do not store messages, messages withheld by an entry filter are not delivered. Reading the policy discloses only the names of the configured entry filters. The issue does not allow reading message contents, and entry filters cannot modify message payloads. Persistent topics and namespace-level entry filter policies are not affected. Apache Pulsar versions before 3.3.0 are not affected, because in those versions the entry filters topic policy check is made in code shared by the persistent and non-persistent endpoints. This issue affects Apache Pulsar versions from 3.3.0 before 4.0.14 and from 4.1.0 before 4.2.5. - 3.3.x and 4.0.x version users should upgrade to at least 4.0.14. - 4.1.x and 4.2.x version users should upgrade to at least 4.2.5. Users operating versions prior to those listed above should upgrade to the aforementioned patched versions or newer versions. The currently supported Apache Pulsar release lines are 4.0.x and 5.0.x. The supported versions schedule is available at https://pulsar.apache.org/contribute/release-policy/. Users who cannot upgrade immediately and have deployed entry filters should keep allowOverrideEntryFilters at its default value of false, so that topic-level entry filter policies do not affect message dispatch. | ||||
| CVE-2026-91427 | 1 Oracle | 1 Siebel Crm Deployment | 2026-10-23 | 2.3 Low |
| Vulnerability in the Siebel CRM Deployment product of Oracle Siebel CRM (component: Server Infrastructure). Supported versions that are affected are 17.0-26.9. Easily exploitable vulnerability allows high privileged attacker with logon to the infrastructure where Siebel CRM Deployment executes to compromise Siebel CRM Deployment. Successful attacks of this vulnerability can result in unauthorized ability to cause a partial denial of service (partial DOS) of Siebel CRM Deployment. CVSS 3.1 Base Score 2.3 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L). | ||||
| CVE-2026-91428 | 1 Oracle | 1 Siebel Crm End User | 2026-10-23 | 4.3 Medium |
| Vulnerability in the Siebel CRM End User product of Oracle Siebel CRM (component: Open UI). Supported versions that are affected are 17.0-26.9. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Siebel CRM End User. Successful attacks require human interaction from a person other than the attacker. Successful attacks of this vulnerability can result in unauthorized update, insert or delete access to some of Siebel CRM End User accessible data. CVSS 3.1 Base Score 4.3 (Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N). | ||||
| CVE-2026-115481 | 1 Baserproject | 1 Basercms | 2026-10-23 | N/A |
| baserCMS is a website development framework. Starting in version 5.0.0-beta1 and prior to versions 5.3.2 and 5.4.2, `PermissionGroupsService::build()` reads a plugin's `config/permission.php` to decide what each user group may reach. When that file is absent it writes a wildcard allow rule instead: `url` `/baser/<prefix>/<plugin>/*`, `method` `*`, `auth` true, for every non-admin group. BcCustomContent has no such file in any release. After an administrator installs it, the default `operators` group can store and execute arbitrary PHP under the document root. Versions 5.3.2 and 5.4.2 patch the issue. | ||||
| CVE-2026-115479 | 1 Baserproject | 1 Basercms | 2026-10-23 | 5.3 Medium |
| baserCMS is a website development framework. In versions 5.2.5 before 5.3.2 and 5.4.0 before 5.4.2, an unauthenticated visitor can supply a comma-separated address list in a public mail form's email field and cause a single auto-reply to be addressed to multiple third parties. MailMessageMailer::sendFormToUser() passes the visitor-controlled userMail value to parseAndNormalizeMailAddresses(), which splits it with explode(',') and supplies every resulting address to setTo(). Newly created forms with an email-type field are affected when the separate, optional VALID_EMAIL server-side validation is not enabled; browser type=email validation does not prevent crafted requests. The bundled contact form enables VALID_EMAIL and is not affected. The auto-reply uses the site's sender identity and includes partially attacker-controlled content, allowing abuse of the site to deliver unsolicited mail. This issue has been patched in versions 5.3.2 and 5.4.2. | ||||
| CVE-2026-115480 | 1 Baserproject | 1 Basercms | 2026-10-23 | 5.3 Medium |
| baserCMS is a website development framework. In versions 5.0.0 before 5.3.2 and 5.4.0 before 5.4.2, the public POST /baser/api/bc-mail/mail_messages/add/{mailContentId}.json endpoint accepts submissions without enforcing the form's auth_captcha setting. BcMail\Controller\Api\MailMessagesController::add() and MailMessagesService::create() omit the BcCaptchaService::check() verification of captcha_id and auth_captcha performed by MailController::submit() in the web UI. An unauthenticated attacker who can reach the API can therefore automate submissions without solving the enabled image challenge. The API disables FormProtection and has no rate limit; submissions can generate administrator-inbox spam, send attacker-influenced auto-replies to third parties when an email field is present, and accumulate mail_messages database records when save_info is enabled. The API already enforces the isAccepting() check added for CVE-2026-30878; the missing CAPTCHA check is a separate control failure. This issue has been patched in versions 5.3.2 and 5.4.2. | ||||
| CVE-2026-114621 | 1 Baserproject | 1 Basercms | 2026-10-23 | 8.8 High |
| baserCMS is a website development framework. In versions 5.0.0 before 5.3.2 and 5.4.0 before 5.4.2, list and detail actions in the Admin and Api/Admin prefixes pass request query parameters, including contain, conditions, fields, finder, and order, directly to the ORM as options. A user able to log into the admin panel can embed SQL fragments in those options to execute arbitrary SQL against the application's database, including reading password hashes from the users table. Public-page and public-API fixes released in 5.3.1 and 5.4.1 did not protect these administrative paths. Setting USE_CORE_ADMIN_API to false does not prevent access through an authenticated browser session. This issue has been patched in versions 5.3.2 and 5.4.2. | ||||
| CVE-2026-114622 | 1 Baserproject | 1 Basercms | 2026-10-23 | 7.2 High |
| baserCMS is a website development framework. In versions 5.2.3 before 5.3.2 and 5.4.0 before 5.4.2, the optional BcThemeFile plugin's Admin API validates a raw path in ThemeFilesService::update() and getFullpath(), but ThemeFileForm::_execute() subsequently applies rawurldecode() to fullpath before writing. Because normalizePath() resolves only literal dot segments, percent-encoded traversal can pass the containment checks and become a path outside the theme directory at the write sink. An authenticated administrator can write PHP files into writable locations such as webroot and execute them, exceeding the intended theme-template editing boundary. The source also identifies the same check-before-decode ordering in ThemeFilesService::copy(), although that path was not dynamically verified. Exploitation requires the non-default plugin, an administrator session, and a same-origin Origin header; USE_CORE_ADMIN_API=false does not block session-authenticated requests. The Admin web form is not affected by this encoded-path tampering because FormProtection protects fullpath. This is a third bypass of the protections associated with CVE-2026-30940, using encoded traversal decoded after validation. This issue has been patched in versions 5.3.2 and 5.4.2. | ||||
| CVE-2026-114623 | 1 Baserproject | 1 Basercms | 2026-10-23 | 6.5 Medium |
| baserCMS is a website development framework. In versions 5.0.0 before 5.3.2 and 5.4.0 before 5.4.2, an authenticated user with only theme-file view permission can traverse outside the theme directory through the optional BcThemeFile plugin's Admin web screen. ThemeFilesController::parseArgs() constructs a path containing literal ../ segments, and the view and edit actions pass it to ThemeFilesService::get() without containment validation. Authorization checks the unresolved request path, after which ThemeFile::_getContents() reads the resolved file and exposes its contents in the form textarea. A client must preserve the dot segments rather than normalize them away. Readable files are limited to .php, .css, .js, and .ctp; this can disclose application source and config/install.php database credentials in MySQL or PostgreSQL deployments, while SQLite configurations have an empty database password. Reading config/app_local.php may expose the Security.salt fallback, which is effective only when not overridden by environment configuration. The flaw does not disclose .env, .pem, or SQLite .db files, does not itself permit file writes or code execution, and does not affect the separate API getFullpath() route. The plugin is disabled by default and unauthenticated requests are not sufficient. This issue has been patched in versions 5.3.2 and 5.4.2. | ||||
| CVE-2026-115478 | 1 The-40-thieves | 1 Obsidian-tc | 2026-10-23 | N/A |
| obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian vaults. From 1.0.1 until 1.31.4, `create_entity`, `link_entities`, `rename_entity`, `unlink_entities` and `delete_entity` regenerate memory notes from SQLite at the computed `memory/<type>/<name>.md` path without reliably preserving note ownership or the consistency of a failed lifecycle operation. During shared materialization, a hand-authored note or an orphan left by a different entity whose name sanitized to the same path could have its entire body overwritten on the next write naming that type and name, with non-owned frontmatter preserved. `rename_entity` also seeded the destination path with a direct atomic write without validating ownership and could overwrite a foreign note there. Separately, several tools mutated SQLite before fallible filesystem work: `create_entity` and `link_entities` inserted the row or relation before materialization; `rename_entity` updated the entity, including a retired status, before updating its note; `unlink_entities` removed a relation before rematerializing the source note; and `delete_entity`'s cascade removed the target and its relations before rematerializing neighbouring notes. A later filesystem failure could therefore leave a row or relation changed and the memory graph inconsistent with the notes on disk even when the operation failed. An authorized caller with the required memory-tool permissions could, without intending to, destroy the body of a vault note outside the entity being written; `delete_entity` additionally requires its deletion permission and destructive confirmation, which this memory flaw does not bypass. Snapshots-before-write through `restore_note` mitigate the overwrite only where snapshots are enabled and the note had previously been written through obsidian-tc. This issue is fixed in version 1.31.4. | ||||
| CVE-2026-87901 | 1 Phpbb | 1 Phpbb | 2026-10-23 | N/A |
| Improper sanitization in the registration module allows reflected Cross-Site Scripting. | ||||
| CVE-2026-79977 | 1 Zephyrproject | 1 Zephyr | 2026-10-23 | 8.2 High |
| The WireGuard VPN service in subsys/net/lib/wireguard/wg.c updated the peer endpoint from a message it could not authenticate. In handle_transport_data(), when the 32-bit receiver index of an incoming transport-data message matched no session, the code both scheduled a new handshake and copied the datagram's source address into peer->endpoint with memcpy(&peer->endpoint, peer_addr, sizeof(peer->endpoint)). Because the receiver index is unknown, there is no key with which such a message could be verified, so the address written into peer->endpoint is entirely attacker-supplied. Every other endpoint update in the implementation happens only after authentication — after the Noise handshake in handle_handshake_init(), or after AEAD decryption plus the anti-replay check in wg_process_data_message(). The WireGuard listener is registered with net_udp_register() using no remote address or port filter and defaults to UDP port 51820 (CONFIG_WIREGUARD_PORT), and wg_ctrl_recv() resolves the peer by interface rather than by any cryptographic identity. Any host able to send a UDP datagram to that port can therefore reach the defect off-path, with no need to observe legitimate traffic: a 16-byte datagram carrying the transport-data type, zeroed reserved bytes and an arbitrary receiver index is sufficient. The vulnerable branch runs whenever the peer has neither a valid handshake nor a current keypair — the state at boot and after a session expires. A single spoofed datagram redirects peer->endpoint to an address of the attacker's choosing, and all subsequent handshake initiations, keepalives and encrypted data packets are sent there. The legitimate peer never receives the initiations and so never re-authenticates, and nothing resets the endpoint afterwards, leaving the tunnel persistently unusable on devices whose peer does not initiate handshakes itself. The attacker can also relay the redirected initiations to the real peer to place itself in the path of the tunnel, observing ciphertext and traffic metadata and selectively dropping packets. WireGuard's end-to-end cryptography still prevents decryption or forgery of tunnel content, so the impact is loss of availability plus limited confidentiality, not key compromise. The fix removes the endpoint learning from this path entirely: the stale-session recovery is kept, but the handshake is sent only to an endpoint learnt from an authenticated message, falling back to the configured cfg_endpoint, and the message is dropped when neither is known. CONFIG_WIREGUARD is marked experimental and is not enabled by default. | ||||
| CVE-2026-79978 | 1 Zephyrproject | 1 Zephyr | 2026-10-23 | 3.6 Low |
| The RTIO streaming completion callback adxl345_process_fifo_samples_cb() in drivers/sensor/adi/adxl345/adxl345_stream.c clamps the amount of FIFO data it will report (read_len = MIN(fifo_bytes, buf_avail)) to the space actually returned by rtio_sqe_rx_buf(), but then queues one 6-byte bus read per hardware FIFO entry at consecutive offsets from read_buf, bounded by the device-reported entry count rather than by the clamp. When the allocated buffer is smaller than a full batch, the driver writes up to 186 bytes past the end of the allocation; a companion defect left data->fifo_total_bytes un-reset at batch start, so an aborted or errored chain could leave a stale write offset that pushes the next batch's writes out of bounds as well. A short buffer is an expected, first-class outcome of the RTIO allocator: rtio_block_pool_alloc() walks the requested size down one block at a time until a contiguous run is available, and the driver only demands sizeof(struct adxl345_fifo_data) + 6 bytes as its minimum. Any streaming configuration whose mempool block granularity is smaller than a full FIFO batch (204 bytes) — for example the sensor shell's RTIO_DEFINE_WITH_MEMPOOL(sensor_read_rtio, 8, 8, 32, 64, 4) used by sensor stream <dev> on fifo_wm incl, or the 16-byte-block streaming example in the documentation — takes this path whenever the pool is fragmented or the consuming thread falls behind. The out-of-bounds writes are performed by the I2C/SPI RTIO backend (DMA on many SoCs) into the shared RTIO block pool, corrupting neighbouring live buffers or, for a pool smaller than one batch, memory beyond the pool itself. The written bytes are accelerometer samples and the destination follows the allocation, so there is no controllable corruption primitive: the realistic impact is silent corruption of other RTIO consumers' data or a crash. Reaching it requires a board with an interrupt-wired ADXL345 built with CONFIG_ADXL345_STREAM, plus buffer-pool starvation, which a co-resident local workload can induce but which also occurs spontaneously under load; there is no network, USB or radio path to this code. | ||||
| CVE-2026-79979 | 1 Zephyrproject | 1 Zephyr | 2026-10-23 | 7.8 High |
| The arm64 MMU backend invalidates a single virtual address from the TLB with invalidate_tlb_page() in arch/arm64/core/mmu.c, which issued TLBI VAE1{IS} with an operand of virt >> 12. That operand encodes the ASID in bits [63:48], so the invalidation only ever matched ASID 0 (the kernel page tables) and global entries. Memory domains, however, are allocated ASIDs starting at 1 in arch_mem_domain_init(), and every domain-private leaf created by private_map() is mapped with MT_NG, i.e. non-global. A domain's cached translation therefore survived the invalidation. All callers of invalidate_tlb_page() are demand-paging paths. When the eviction algorithm reclaims a frame, page_frame_prepare_locked() in kernel/mmu.c calls arch_mem_page_out(), which marks the kernel leaf invalid, propagates the invalid descriptor into every domain via sync_domains(), and then flushes only ASID 0. do_page_fault() immediately reuses the very same page frame for the incoming mapping through arch_mem_page_in(). A user thread that had already touched the evicted page — a k_mem_partition added with arch_mem_domain_partition_add(), or its own stack mapped by map_thread_stack() — retains a valid EL0 read/write translation to that physical frame under its own ASID. Unprivileged code running in a user thread can drive memory pressure to force eviction and then keep accessing the stale address, obtaining read and write access to whatever the kernel subsequently placed in that frame: supervisor data, another memory domain's partition, or another thread's stack. This defeats the isolation that CONFIG_USERSPACE is meant to enforce, allowing information disclosure and memory corruption up to full compromise of the system. The fix switches the implementation to TLBI VAAE1{IS}, which matches every ASID and both global and non-global entries, so no domain-tagged translation survives a page out, dirty-bit update or access-flag clear. Exploitation requires an arm64 build with both CONFIG_USERSPACE and CONFIG_DEMAND_PAGING enabled, an active backing store, and at least one demand-paged page that is also privately mapped into a user memory domain. The same commit additionally stops globalize_table() from stripping EL0 permission and non-global attributes off domain-private leaves during paging synchronization, which previously caused user threads to lose access to their own partitions and stacks. | ||||
| CVE-2026-79980 | 1 Zephyrproject | 1 Zephyr | 2026-10-23 | 5.6 Medium |
| The DHCPv4 client in subsys/net/lib/dhcpv4/dhcpv4.c maintained its transaction identifier (iface->config.dhcpv4.xid) as a counter rather than as a per-transaction random value. It was seeded once with sys_rand32_get() in dhcpv4_start_internal(), incremented by one in dhcpv4_send_discover() and dhcpv4_send_decline(), and never changed by dhcpv4_send_request() — so every RENEWING and REBINDING exchange reused, unchanged, the identifier that had already appeared on the wire in the broadcast DHCPDISCOVER at boot, and where the identifier did move it moved predictably by one. RFC 2131 4.1 requires a single identifier per transaction, chosen so that clients are unlikely to collide. This identifier is the client's only unpredictable reply-validation token. net_dhcpv4_input() accepts a BOOTP reply on op, a matching xid, and a matching chaddr (the interface MAC, which is public); the UDP callback is registered with a wildcard remote address and port, and no server-identifier or source-address check is applied. An attacker who learns one identifier — for example any host on the same segment that sees the broadcast DHCPDISCOVER, or a DHCP server or relay on a network the device previously joined — therefore retains a valid token for the device's whole uptime, and can predict the identifiers of later exchanges, without having to observe the unicast renew traffic or race the legitimate server. A forged reply that passes those checks has effect regardless of client state, because dhcpv4_parse_options() applies its side effects before the state machine gate in dhcpv4_handle_reply(): the router option calls net_if_ipv4_set_gw() and the DNS option calls dns_resolve_reconfigure(). A single accepted datagram can thus repoint the device's default gateway and resolvers at attacker-controlled addresses, redirecting its traffic; during RENEWING or REBINDING a forged DHCPACK re-binds the lease with attacker-chosen parameters and a forged DHCPNAK removes the address and restarts configuration. The fix draws a fresh sys_rand32_get() value at each point where a transaction begins — entering SELECTING, RENEWING and REBINDING, and at the INIT/INIT-REBOOT entry taken when an interface with a lease goes down — while REQUESTING and DECLINE keep the identifier of the exchange they belong to, as RFC 2131 requires. As a side effect the client also no longer discards a slow server's offer after retransmitting a discover, and the initial-discover backoff now draws its own randomness instead of deriving it from the identifier. | ||||
| CVE-2026-79981 | 1 Zephyrproject | 1 Zephyr | 2026-10-23 | 6.5 Medium |
| The DNS stub resolver in subsys/net/lib/dns/resolve.c binds one UDP socket per configured server when the resolver context is initialised (dns_resolve_init_locked() -> register_dispatcher() -> dns_dispatcher_register()), with the local port left at 0 so the stack picks an ephemeral port exactly once. dns_write() then sends every subsequent query from that same socket without re-binding, so the source port is constant for the lifetime of the resolver context while only the 16-bit transaction identifier (ctx->queries[i].id, drawn with sys_rand16_get()) varies per query. RFC 5452 section 9.2 requires both to vary; with a fixed port, an off-path attacker has to guess only the identifier. The stable port is cheap to learn. Any single observed query reveals it permanently, and it can also be found by probing the ephemeral UDP range: subsys/net/ip/connection.c answers unmatched unicast UDP with an ICMP port-unreachable, so the resolver's socket is the one port in that range that stays silent. Acceptance of a reply is decided solely by get_slot_by_id() matching the transaction identifier and a CRC-16 of the queried name — the reply's source address is never checked (dispatcher_cb() does ARG_UNUSED(addr)), so forged answers need not even be spoofed to appear to come from the configured server; they only need to reach the resolver's port. An attacker with UDP reachability to the device (same LAN, Wi-Fi or mesh segment, or a globally routable device address) can therefore flood answers for a predictable query name across the 16-bit identifier space during a query window and race the legitimate server. A win makes the application resolve an attacker-chosen address, and with CONFIG_DNS_RESOLVER_CACHE enabled the forged record is retained for its attacker-chosen TTL. The attack still requires winning that race, and applications that validate TLS certificates for the resolved endpoint are largely protected. The fix draws a fresh local port before each query to a server that has nothing outstanding: dns_randomize_source_port() unregisters the dispatcher, closes and reopens the socket, and re-registers it bound to port 0 so the system selects a new port, raising the per-query guessing space from roughly 16 to roughly 31 bits. Multicast DNS and LLMNR are excluded because their ports are protocol-fixed. The behaviour is controlled by CONFIG_DNS_RESOLVER_RANDOMIZE_SOURCE_PORT (default y). | ||||