When an incoming DNS protocol message includes a Transaction Signature (TSIG), BIND always checks it. If the TSIG contains an invalid value in the algorithm field, BIND immediately aborts with an assertion failure. This issue affects BIND 9 versions 9.20.0 through 9.20.8 and 9.21.0 through 9.21.7.

The version of ISC BIND installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the cve-2025-40775 advisory.

  - When an incoming DNS protocol message includes a Transaction Signature (TSIG), BIND always checks it. If     the TSIG contains an invalid value in the algorithm field, BIND immediately aborts with an assertion     failure. This issue affects BIND 9 versions 9.20.0 through 9.20.8 and 9.21.0 through 9.21.7.
    (CVE-2025-40775)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of bind installed on the remote Azure Linux 3.0 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the CVE-2025-40775 advisory.

  - When an incoming DNS protocol message includes a Transaction Signature (TSIG), BIND always checks it. If     the TSIG contains an invalid value in the algorithm field, BIND immediately aborts with an assertion     failure. This issue affects BIND 9 versions 9.20.0 through 9.20.8 and 9.21.0 through 9.21.7.
    (CVE-2025-40775)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2025:01787-1 advisory.

    Update to version 9.20.9.

    - Security issues fixed:

      * CVE-2025-40775: denial-of-service due to assertion failure caused by the processing of a NS message     with an invalid         TSIG (bsc#1243361).
      * CVE-2024-12705: CPU and memory exhaustion due to DNS-over-HTTPS issues that arise under heavy query     load         (bsc#1236597).
      * CVE-2024-11187: CPU exhaustion when processing queries that lead to responses containing several     records in the         Additional data section (bsc#1236596).

    - Changelog:

      - Feature changes:
        * Performance optimization for NSEC3 lookups introduced in BIND 9.20.2           was reverted to avoid risks associated with a complex code change.
        * The configuration clauses parental-agents and primaries are renamed           to remote-servers.
        * Add none parameter to query-source and query-source-v6 to disable           IPv4 or IPv6 upstream queries but allow listening to queries from           clients on IPv4 or IPv6.
        * dnssec-ksr now supports KSK rollovers.
        * Print RFC 7314: EXPIRE option in transfer summary.
        * Emit more helpful log messages for exceeding max-records-per-type.
        * Harden key management when key files have become unavailable.

      - New Features:
        * Add support for EDE 20 (Not Authoritative).
        * Add support for EDE 7 and EDE 8.
        * `dig` can now display the received BADVERS message during           negotiation.
        * Add an `rndc` command to reset some statistics counters.
        * Implement the min-transfer-rate-in configuration option.
        * Add HTTPS record query to host command line tool.
        * Implement sig0key-checks-limit and sig0message-checks-limit.
        * Adds support for EDE code 1 and 2.
        * Add an rndc command to toggle jemalloc profiling.
        * Add support for multiple extended DNS errors.
        * Print the expiration time of stale records.
        * Add Extended DNS Error Code 22 - No Reachable Authority.
        * Add a new option to configure the maximum number of outgoing queries           per client request.
        * Use the Server Name Indication (SNI) extension for all outgoing TLS           connections.
        * Update built-in bind.keys file with the new 2025 IANA root key.
        * Add an initial-ds entry to bind.keys for the new root key, ID           38696, which is scheduled for publication in January 2025.

      - Bug Fixes:
        * Restore NSEC3 closest-encloser lookup improvements.
        * Stop caching lack of EDNS support.
        * Fix resolver statistics counters for timed-out responses.
        * Nested DNS validation could cause an assertion failure.
        * Wait for memory reclamation to finish in `named-checkconf`.
        * Ensure `max-clients-per-query` is at least `clients-per-query`.
        * Fix write after free in validator code.
        * Don't enforce NOAUTH/NOCONF flags in DNSKEYs.
        * Fix several small DNSSEC timing issues.
        * Fix inconsistency in CNAME/DNAME handling during resolution.
        * Fix dual-stack-servers configuration option.
        * Fix a data race causing a permanent active client increase.
        * Fix deferred validation of unsigned DS and DNSKEY records.
        * Fix RPZ race condition during a reconfiguration.
        * 'CNAME and other data check' not applied to all types.
        * Relax private DNSKEY and RRSIG constraints.
        * Remove NSEC/DS/NSEC3 RRSIG check from dns_message_parse().
        * Fix TTL issue with ANY queries processed through RPZ 'passthru';.
        * dnssec-signzone needs to check for a NULL key when setting offline.
        * Fix a bug in the statistics channel when querying zone transfer           information.
        * Fix assertion failure when dumping recursing clients.
        * Dump the active resolver fetches from dns_resolver_dumpfetches().
        * Recently expired records could be returned with a timestamp in           future.
        * YAML string not terminated in negative response in delv.
        * Fix a bug in dnssec-signzone related to keys being offline.
        * Apply the memory limit only to ADB database items.
        * Avoid unnecessary locking in the zone/cache database.
        * Fix reporting of Extended DNS Error 22 (No Reachable Authority).
        * Fix nsupdate hang when processing a large update.
        * Fix possible assertion failure when reloading server while           processing update policy rules.
        * Preserve cache across reconfig when using attach-cache.
        * Resolve the spurious drops in performance due to glue cache.
        * Fix dnssec-signzone signing non-DNSKEY RRsets with revoked keys.
        * Fix improper handling of unknown directives in resolv.conf.
        * Fix response policy zones and catalog zones with an $INCLUDE           statement defined.
        * Use TLS for notifies if configured to do so.
        * Notifies configured to use TLS will now be sent over TLS, instead of           plain text UDP or TCP. Also, failing to load the TLS           configuration for notify now results in an error.'
        * {&dns} is as valid as {?dns} in a SVCB's dohpath.
        * dig failed to parse a valid SVCB record with a dohpath URI template           containing a {&dns}, like           'dohpath=/some/path?key=value{&dns}';.
        * Fix NSEC3 closest encloser lookup for names with empty non-terminals.
        * A previous performance optimization for finding the NSEC3 closest           encloser when generating authoritative responses could cause servers           to return incorrect NSEC3 records in some cases. This has been fixed.
        * recursive-clients statement with value 0 triggered an assertion           failure.
        * BIND 9.20.0 broke recursive-clients 0;. This has now been fixed.
        * Parsing of hostnames in rndc.conf was broken.
        * When DSCP support was removed, parsing of hostnames in rndc.conf was           accidentally broken, resulting in an assertion failure. This has been           fixed.
        * `dig` options of the form [+-]option=<value> failed to display           the value on the printed command line. This has been fixed.
        * Provide more visibility into TLS configuration errors by logging           SSL_CTX_use_certificate_chain_file() and           SSL_CTX_use_PrivateKey_file() errors individually.
        * Fix a race condition when canceling ADB find which could cause an           assertion failure.
        * SERVFAIL cache memory cleaning is now more aggressive; it no longer           consumes a lot of memory if the server encounters many SERVFAILs at           once.
        * Fix trying the next primary XoT server when the previous one was           marked as unreachable.
        * In some cases named failed to try the next primary server in the           primaries list when the previous one was marked as unreachable. This           has been fixed.

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

An update of the bindutils package has been released.

The remote Ubuntu 24.10 / 25.04 host has packages installed that are affected by a vulnerability as referenced in the USN-7526-1 advisory.

    It was discovered that Bind incorrectly handled certain DNS messages with invalid TSIG. A remote attacker     could possibly use this issue to cause Bind to crash, resulting in a denial of service.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
298816	ISC BIND 9.20.0 < 9.20.9 / 9.21.0 < 9.21.8 Assertion Failure (cve-2025-40775)	Nessus	DNS	high
295766	Azure Linux 3.0 Security Update: bind (CVE-2025-40775)	Nessus	Azure Linux Local Security Checks	high
237601	SUSE SLED15 / SLES15 Security Update : bind (SUSE-SU-2025:01787-1)	Nessus	SuSE Local Security Checks	high
237574	Photon OS 5.0: Bindutils PHSA-2025-5.0-0525	Nessus	PhotonOS Local Security Checks	high
237026	Ubuntu 24.10 / 25.04 : Bind vulnerability (USN-7526-1)	Nessus	Ubuntu Local Security Checks	high

Detections

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CVE-2025-40775

high

Tenable Plugins

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high

high

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high