Asterisk is an open source private branch exchange and telephony toolkit. In Asterisk versions 18.20.0 and prior, 20.5.0 and prior, and 21.0.0; as well as ceritifed-asterisk 18.9-cert5 and prior, the 'update' functionality of the PJSIP_HEADER dialplan function can exceed the available buffer space for storing the new value of a header. By doing so this can overwrite memory or cause a crash. This is not externally exploitable, unless dialplan is explicitly written to update a header based on data from an outside source. If the 'update' functionality is not used the vulnerability does not occur. A patch is available at commit a1ca0268254374b515fa5992f01340f7717113fa.

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 and telephony toolkit. In Asterisk versions 18.20.0 and     prior, 20.5.0 and prior, and 21.0.0; as well as ceritifed-asterisk 18.9-cert5 and prior, the 'update'     functionality of the PJSIP_HEADER dialplan function can exceed the available buffer space for storing the     new value of a header. By doing so this can overwrite memory or cause a crash. This is not externally     exploitable, unless dialplan is explicitly written to update a header based on data from an outside     source. If the 'update' functionality is not used the vulnerability does not occur. A patch is available     at commit a1ca0268254374b515fa5992f01340f7717113fa. (CVE-2023-37457)

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:

  - PJSIP is a free and open source multimedia communication library written in C language implementing
    standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. Buffer overread is possible when
    parsing a specially crafted STUN message with unknown attribute. The vulnerability affects applications
    that uses STUN including PJNATH and PJSUA-LIB. The patch is available as a commit in the master branch
    (2.13.1). (CVE-2022-23537)

  - Asterisk is an open source private branch exchange and telephony toolkit. In Asterisk versions 18.20.0 and
    prior, 20.5.0 and prior, and 21.0.0; as well as ceritifed-asterisk 18.9-cert5 and prior, the 'update'
    functionality of the PJSIP_HEADER dialplan function can exceed the available buffer space for storing the
    new value of a header. By doing so this can overwrite memory or cause a crash. This is not externally
    exploitable, unless dialplan is explicitly written to update a header based on data from an outside
    source. If the 'update' functionality is not used the vulnerability does not occur. A patch is available
    at commit a1ca0268254374b515fa5992f01340f7717113fa. (CVE-2023-37457)

  - Asterisk is an open source private branch exchange and telephony toolkit. In Asterisk prior to versions
    18.20.1, 20.5.1, and 21.0.1, as well as certified-asterisk prior to 18.9-cert6, it is possible to read any
    arbitrary file even when the `live_dangerously` is not enabled. This allows arbitrary files to be read.
    Asterisk versions 18.20.1, 20.5.1, and 21.0.1, as well as certified-asterisk prior to 18.9-cert6, contain
    a fix for this issue. (CVE-2023-49294)

  - Asterisk is an open source private branch exchange and telephony toolkit. In Asterisk prior to versions
    18.20.1, 20.5.1, and 21.0.1; as well as certified-asterisk prior to 18.9-cert6; Asterisk is susceptible to
    a DoS due to a race condition in the hello handshake phase of the DTLS protocol when handling DTLS-SRTP
    for media setup. This attack can be done continuously, thus denying new DTLS-SRTP encrypted calls during
    the attack. Abuse of this vulnerability may lead to a massive Denial of Service on vulnerable Asterisk
    servers for calls that rely on DTLS-SRTP. Commit d7d7764cb07c8a1872804321302ef93bf62cba05 contains a fix,
    which is part of versions 18.20.1, 20.5.1, 21.0.1, amd 18.9-cert6. (CVE-2023-49786)

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. In Asterisk versions 18.20.0 and
    prior, 20.5.0 and prior, and 21.0.0; as well as ceritifed-asterisk 18.9-cert5 and prior, the 'update'
    functionality of the PJSIP_HEADER dialplan function can exceed the available buffer space for storing the
    new value of a header. By doing so this can overwrite memory or cause a crash. This is not externally
    exploitable, unless dialplan is explicitly written to update a header based on data from an outside
    source. If the 'update' functionality is not used the vulnerability does not occur. A patch is available
    at commit a1ca0268254374b515fa5992f01340f7717113fa. (CVE-2023-37457)

  - Asterisk is an open source private branch exchange and telephony toolkit. In Asterisk prior to versions
    18.20.1, 20.5.1, and 21.0.1, as well as certified-asterisk prior to 18.9-cert6, it is possible to read any
    arbitrary file even when the `live_dangerously` is not enabled. This allows arbitrary files to be read.
    Asterisk versions 18.20.1, 20.5.1, and 21.0.1, as well as certified-asterisk prior to 18.9-cert6, contain
    a fix for this issue. (CVE-2023-49294)

  - Asterisk is an open source private branch exchange and telephony toolkit. In Asterisk prior to versions
    18.20.1, 20.5.1, and 21.0.1; as well as certified-asterisk prior to 18.9-cert6; Asterisk is susceptible to
    a DoS due to a race condition in the hello handshake phase of the DTLS protocol when handling DTLS-SRTP
    for media setup. This attack can be done continuously, thus denying new DTLS-SRTP encrypted calls during
    the attack. Abuse of this vulnerability may lead to a massive Denial of Service on vulnerable Asterisk
    servers for calls that rely on DTLS-SRTP. Commit d7d7764cb07c8a1872804321302ef93bf62cba05 contains a fix,
    which is part of versions 18.20.1, 20.5.1, 21.0.1, amd 18.9-cert6. (CVE-2023-49786)

The remote Debian 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-3696 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-3696-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                      Markus Koschany     December 28, 2023                             https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : asterisk     Version        : 1:16.28.0~dfsg-0+deb10u4     CVE ID         : CVE-2023-37457 CVE-2023-38703 CVE-2023-49294 CVE-2023-49786     Debian Bug     : 1059303 1059032 1059033

    Multiple security vulnerabilities have been discovered in Asterisk, an Open     Source Private Branch Exchange.

    CVE-2023-37457

        The 'update' functionality of the PJSIP_HEADER dialplan function can exceed         the available buffer space for storing the new value of a header. By doing         so this can overwrite memory or cause a crash. This is not externally         exploitable, unless dialplan is explicitly written to update a header based         on data from an outside source. If the 'update' functionality is not used         the vulnerability does not occur.

    CVE-2023-38703

        PJSIP is a free and open source multimedia communication library written in         C with high level API in C, C++, Java, C#, and Python languages. SRTP is a         higher level media transport which is stacked upon a lower level media         transport such as UDP and ICE. Currently a higher level transport is not         synchronized with its lower level transport that may introduce a         use-after-free issue. This vulnerability affects applications that have         SRTP capability (`PJMEDIA_HAS_SRTP` is set) and use underlying media         transport other than UDP. This vulnerabilitys impact may range from         unexpected application termination to control flow hijack/memory         corruption.

    CVE-2023-49294

        It is possible to read any arbitrary file even when the `live_dangerously`         option is not enabled.

    CVE-2023-49786

       Asterisk is susceptible to a DoS due to a race condition in the hello        handshake phase of the DTLS protocol when handling DTLS-SRTP for media        setup. This attack can be done continuously, thus denying new DTLS-SRTP        encrypted calls during the attack. Abuse of this vulnerability may lead to        a massive Denial of Service on vulnerable Asterisk servers for calls that        rely on DTLS-SRTP.

    For Debian 10 buster, these problems have been fixed in version     1:16.28.0~dfsg-0+deb10u4.

    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     Attachment:
    signature.asc     Description: This is a digitally signed message part

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.

The remote host is affected by the vulnerability described in GLSA-202412-03 (Asterisk: Multiple Vulnerabilities)

    Multiple vulnerabilities have been discovered in Asterisk. Please review the CVE identifiers referenced     below for details.

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

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

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

  - PJSIP is a free and open source multimedia communication library written in C language implementing
    standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. Buffer overread is possible when
    parsing a specially crafted STUN message with unknown attribute. The vulnerability affects applications
    that uses STUN including PJNATH and PJSUA-LIB. The patch is available as a commit in the master branch
    (2.13.1). (CVE-2022-23537)

  - In Sangoma Asterisk through 16.28.0, 17.x and 18.x through 18.14.0, and 19.x through 19.6.0, an incoming
    Setup message to addons/ooh323c/src/ooq931.c with a malformed Calling or Called Party IE can cause a
    crash. (CVE-2022-37325)

  - A use-after-free in res_pjsip_pubsub.c in Sangoma Asterisk 16.28, 18.14, 19.6, and certified/18.9-cert2
    may allow a remote authenticated attacker to crash Asterisk (denial of service) by performing activity on
    a subscription via a reliable transport at the same time that Asterisk is also performing activity on that
    subscription. (CVE-2022-42705)

  - An issue was discovered in Sangoma Asterisk through 16.28, 17 and 18 through 18.14, 19 through 19.6, and
    certified through 18.9-cert1. GetConfig, via Asterisk Manager Interface, allows a connected application to
    access files outside of the asterisk configuration directory, aka Directory Traversal. (CVE-2022-42706)

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
252354	Linux Distros Unpatched Vulnerability : CVE-2023-37457	Nessus	Misc.	high
425703	Alpine: multiple asterisk packages: security update to 18.20.2-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	critical
425703	Alpine: multiple asterisk packages: security update to 18.20.2-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	critical
423711	Alpine: multiple asterisk packages: security update to 20.5.1-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	high
423711	Alpine: multiple asterisk packages: security update to 20.5.1-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
214468	Debian dla-3696 : asterisk - security update	Nessus	Debian Local Security Checks	critical
212188	GLSA-202412-03 : Asterisk: Multiple Vulnerabilities	Nessus	Gentoo Local Security Checks	critical
408227	Alpine: asterisk: security update to 18.20.2-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	critical
408227	Alpine: asterisk: security update to 18.20.2-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	critical

Detections

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CVE-2023-37457

high

Tenable Plugins

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critical

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critical