Asterisk is an open-source private branch exchange (PBX). Prior to versions 18.24.3, 20.9.3, and 21.4.3 of Asterisk and versions 18.9-cert12 and 20.7-cert2 of certified-asterisk, if Asterisk attempts to send a SIP request to a URI whose host portion starts with `.1` or `[.1]`, and res_resolver_unbound is loaded, Asterisk will crash with a SEGV. To receive a patch, users should upgrade to one of the following versions: 18.24.3, 20.9.3, 21.4.3, certified-18.9-cert12, certified-20.7-cert2. Two workarounds are available. Disable res_resolver_unbound by setting `noload = res_resolver_unbound.so` in modules.conf, or set `rewrite_contact = yes` on all PJSIP endpoints. NOTE: This may not be appropriate for all Asterisk configurations.

The remote Fedora 42 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-98decbde87 advisory.

    Update to Asterisk 18.26.4, addressing numerous security vulnerabilities     accumulated since the long-stale 18.12.1 package. The following CVEs are fixed     in this update:

    - CVE-2022-26498 (fixed in 18.13.0): use-after-free in chan_ooh323
    - CVE-2022-42705 (fixed in 18.15.0): use-after-free in res_pjsip_pubsub
    - CVE-2022-37325 (fixed in 18.15.1): crash in H323 channel via malformed IE
    - CVE-2023-37457 (fixed in 18.20.0): buffer overflow in PJSIP_HEADER function
    - CVE-2023-49294 (fixed in 18.20.1): arbitrary file read via AMI GetConfig
    - CVE-2023-49786 (fixed in 18.20.1): DTLS race condition causing DoS
    - CVE-2024-35190 (fixed in 18.23.1): unauthorized SIP requests matched as endpoint
    - CVE-2024-42365 (fixed in 18.24.2): Write=originate allows code execution
    - CVE-2024-42491 (fixed in 18.25.0): crash via malformed Contact/Record-Route URI
    - CVE-2025-49832 (fixed in 18.26.3): DoS/RCE in res_stir_shaken
    - CVE-2025-47779 (fixed in 18.26.2): identity forging via malformed From header
    - CVE-2025-1131  (fixed in 18.26.3): local privilege escalation via safe_asterisk
    - CVE-2025-54995 (fixed in 18.26.4): resource exhaustion via RTP port leak

    Also fixes F44FailsToInstall for asterisk-snmp (BZ#2433748).

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

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

The remote Fedora 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-80b21debe7 advisory.

    Update to Asterisk 18.26.4, addressing numerous security vulnerabilities     accumulated since the long-stale 18.12.1 package. The following CVEs are fixed     in this update:

    - CVE-2022-26498 (fixed in 18.13.0): use-after-free in chan_ooh323
    - CVE-2022-42705 (fixed in 18.15.0): use-after-free in res_pjsip_pubsub
    - CVE-2022-37325 (fixed in 18.15.1): crash in H323 channel via malformed IE
    - CVE-2023-37457 (fixed in 18.20.0): buffer overflow in PJSIP_HEADER function
    - CVE-2023-49294 (fixed in 18.20.1): arbitrary file read via AMI GetConfig
    - CVE-2023-49786 (fixed in 18.20.1): DTLS race condition causing DoS
    - CVE-2024-35190 (fixed in 18.23.1): unauthorized SIP requests matched as endpoint
    - CVE-2024-42365 (fixed in 18.24.2): Write=originate allows code execution
    - CVE-2024-42491 (fixed in 18.25.0): crash via malformed Contact/Record-Route URI
    - CVE-2025-49832 (fixed in 18.26.3): DoS/RCE in res_stir_shaken
    - CVE-2025-47779 (fixed in 18.26.2): identity forging via malformed From header
    - CVE-2025-1131  (fixed in 18.26.3): local privilege escalation via safe_asterisk
    - CVE-2025-54995 (fixed in 18.26.4): resource exhaustion via RTP port leak

    Also fixes F44FailsToInstall for asterisk-snmp (BZ#2433748).

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

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

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-38d71393c1 advisory.

    Update to Asterisk 18.26.4, addressing numerous security vulnerabilities     accumulated since the long-stale 18.12.1 package. The following CVEs are fixed     in this update:

    - CVE-2022-26498 (fixed in 18.13.0): use-after-free in chan_ooh323
    - CVE-2022-42705 (fixed in 18.15.0): use-after-free in res_pjsip_pubsub
    - CVE-2022-37325 (fixed in 18.15.1): crash in H323 channel via malformed IE
    - CVE-2023-37457 (fixed in 18.20.0): buffer overflow in PJSIP_HEADER function
    - CVE-2023-49294 (fixed in 18.20.1): arbitrary file read via AMI GetConfig
    - CVE-2023-49786 (fixed in 18.20.1): DTLS race condition causing DoS
    - CVE-2024-35190 (fixed in 18.23.1): unauthorized SIP requests matched as endpoint
    - CVE-2024-42365 (fixed in 18.24.2): Write=originate allows code execution
    - CVE-2024-42491 (fixed in 18.25.0): crash via malformed Contact/Record-Route URI
    - CVE-2025-49832 (fixed in 18.26.3): DoS/RCE in res_stir_shaken
    - CVE-2025-47779 (fixed in 18.26.2): identity forging via malformed From header
    - CVE-2025-1131  (fixed in 18.26.3): local privilege escalation via safe_asterisk
    - CVE-2025-54995 (fixed in 18.26.4): resource exhaustion via RTP port leak

    Also fixes F44FailsToInstall for asterisk-snmp (BZ#2433748).

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

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

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Asterisk is an open-source private branch exchange (PBX). Prior to versions 18.24.3, 20.9.3, and 21.4.3 of     Asterisk and versions 18.9-cert12 and 20.7-cert2 of certified-asterisk, if Asterisk attempts to send a SIP     request to a URI whose host portion starts with `.1` or `[.1]`, and res_resolver_unbound is loaded,     Asterisk will crash with a SEGV. To receive a patch, users should upgrade to one of the following     versions: 18.24.3, 20.9.3, 21.4.3, certified-18.9-cert12, certified-20.7-cert2. Two workarounds are     available. Disable res_resolver_unbound by setting `noload = res_resolver_unbound.so` in modules.conf, or     set `rewrite_contact = yes` on all PJSIP endpoints. NOTE: This may not be appropriate for all Asterisk     configurations. (CVE-2024-42491)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - Asterisk is an open source private branch exchange and telephony toolkit. After upgrade to 18.23.0, ALL
    unauthorized SIP requests are identified as PJSIP Endpoint of local asterisk server. This vulnerability is
    fixed in 18.23.1, 20.8.1, and 21.3.1. (CVE-2024-35190)

  - Asterisk is an open source private branch exchange (PBX) and telephony toolkit. Prior to asterisk versions
    18.24.2, 20.9.2, and 21.4.2 and certified-asterisk versions 18.9-cert11 and 20.7-cert2, an AMI user with
    `write=originate` may change all configuration files in the `/etc/asterisk/` directory. This occurs
    because they are able to curl remote files and write them to disk, but are also able to append to existing
    files using the `FILE` function inside the `SET` application. This issue may result in privilege
    escalation, remote code execution and/or blind server-side request forgery with arbitrary protocol.
    Asterisk versions 18.24.2, 20.9.2, and 21.4.2 and certified-asterisk versions 18.9-cert11 and 20.7-cert2
    contain a fix for this issue. (CVE-2024-42365)

  - Asterisk is an open-source private branch exchange (PBX). Prior to versions 18.24.3, 20.9.3, and 21.4.3 of
    Asterisk and versions 18.9-cert12 and 20.7-cert2 of certified-asterisk, if Asterisk attempts to send a SIP
    request to a URI whose host portion starts with `.1` or `[.1]`, and res_resolver_unbound is loaded,
    Asterisk will crash with a SEGV. To receive a patch, users should upgrade to one of the following
    versions: 18.24.3, 20.9.3, 21.4.3, certified-18.9-cert12, certified-20.7-cert2. Two workarounds are
    available. Disable res_resolver_unbound by setting `noload = res_resolver_unbound.so` in modules.conf, or
    set `rewrite_contact = yes` on all PJSIP endpoints. NOTE: This may not be appropriate for all Asterisk
    configurations. (CVE-2024-42491)

The remote Debian 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-3925 advisory.

    - -------------------------------------------------------------------------     Debian LTS Advisory DLA-3925-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                    Thorsten Alteholz     October 20, 2024                              https://wiki.debian.org/LTS
    - -------------------------------------------------------------------------

    Package        : asterisk     Version        : 1:16.28.0~dfsg-0+deb11u5     CVE ID         : CVE-2024-42365 CVE-2024-42491


    Two issues have been found in asterisk, an Open Source Private Branch     Exchange.


    CVE-2024-42365

        Due to a privilege escalation, remote code execution and/or         blind server-side request forgery with arbitrary protocol are         possible.

    CVE-2024-42491

        Due to bad handling of malformed Contact or Record-Route URI in an         incoming  SIP request, Asterisk might crash when res_resolver_unbound         is used.

    Thanks to Niels Galjaard, a minor privilege escalation has been fixed.
    More information about ths can be found at:

    https://alioth-lists.debian.net/pipermail/pkg-voip-maintainers/2024-July/038664.html


    For Debian 11 bullseye, these problems have been fixed in version     1:16.28.0~dfsg-0+deb11u5.

    We recommend that you upgrade your asterisk packages.

    For the detailed security status of asterisk please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/asterisk

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS

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

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

ID	Name	Product	Family	Severity
311158	Fedora 42 : asterisk (2026-98decbde87)	Nessus	Fedora Local Security Checks	high
311157	Fedora 43 : asterisk (2026-80b21debe7)	Nessus	Fedora Local Security Checks	high
311100	Fedora 44 : asterisk (2026-38d71393c1)	Nessus	Fedora Local Security Checks	high
252341	Linux Distros Unpatched Vulnerability : CVE-2024-42491	Nessus	Misc.	medium
425704	Alpine: multiple asterisk packages: security update to 18.24.3-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	high
425704	Alpine: multiple asterisk packages: security update to 18.24.3-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
423718	Alpine: multiple asterisk packages: security update to 20.9.3-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	high
423718	Alpine: multiple asterisk packages: security update to 20.9.3-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
209341	Debian dla-3925 : asterisk - security update	Nessus	Debian Local Security Checks	high
408526	Alpine: asterisk: security update to 18.24.3-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	high
408526	Alpine: asterisk: security update to 18.24.3-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high

Detections

Analytics

CVE-2024-42491

medium

Tenable Plugins

high

high

high

medium

high

high

high

high

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high