An issue was discovered in phpseclib 1.x before 1.0.23, 2.x before 2.0.47, and 3.x before 3.0.36. When processing the ASN.1 object identifier of a certificate, a sub identifier may be provided that leads to a denial of service (CPU consumption for decodeOID).

The remote Debian 11 host has a package installed that is affected by multiple vulnerabilities as referenced in the dla-4670 advisory.

    - -----------------------------------------------------------------------     Debian LTS Advisory DLA-4670-1              debian-lts@lists.debian.org     https://www.debian.org/lts/security/                      Utkarsh Gupta     July 05, 2026                               https://wiki.debian.org/LTS
    - -----------------------------------------------------------------------

    Package        : php-phpseclib     Version        : 2.0.30-2+deb11u3     CVE ID         : CVE-2023-52892 CVE-2026-32935 CVE-2026-40194                      CVE-2026-44167 CVE-2026-55599     Debian Bug     : 1131483

    Several vulnerabilities were discovered in phpseclib, a PHP secure     communications library, which could result in hostname validation     bypass, timing side-channel attacks, denial of service, and     server-side request forgery (SSRF).

    CVE-2023-52892

        X509.php did not properly escape regular expression special         characters in a certificate's subjectAltName, allowing a crafted         certificate to bypass hostname validation in validateURL().

    CVE-2026-32935

        The block cipher unpadding routine in Crypt/Base.php used a         short-circuiting comparison, creating a timing side channel that         could aid padding-oracle-style attacks.

    CVE-2026-40194

        The SSH2 implementation compared incoming packet HMACs using a         variable-time string comparison, creating a timing side channel         on cryptographic material.

    CVE-2026-44167

        The ASN.1 decoder's 4096-byte Object Identifier limit (mitigating         CVE-2024-27355) was still large enough to allow an OID         amplification denial of service via crafted ASN.1 structures.

    CVE-2026-55599

        File_X509 could automatically fetch a URL from a certificate's         Authority Information Access extension without validating the         destination, allowing SSRF via a crafted certificate.

    For Debian 11 bullseye, these problems have been fixed in version     2.0.30-2+deb11u3.

    We recommend that you upgrade your php-phpseclib packages.

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

    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.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - An issue was discovered in phpseclib 1.x before 1.0.23, 2.x before 2.0.47, and 3.x before 3.0.36. When
    processing the ASN.1 object identifier of a certificate, a sub identifier may be provided that leads to a
    denial of service (CPU consumption for decodeOID). (CVE-2024-27355)

The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-7404-1 advisory.

    It was discovered that phpseclib did not correctly handle RSA PKCS#1 v1.5 signature verification. An     attacker could possibly use this issue to bypass authentication. This issue only affected Ubuntu 20.04     LTS. (CVE-2021-30130)

    It was discovered that phpseclib did not correctly handle certain characters in certain TLS fields, which     could lead to name confusion. An attacker could possibly use this issue to bypass authentication.
    (CVE-2023-52892)

    It was discovered that phpseclib incorrectly limited the size of prime numbers generated by isPrime. An     attacker could possibly use this issue to cause a denial of service. (CVE-2024-27354)

    It was discovered that phpseclib did not correctly handle processing the ASN.1 object identifier of a     certificate. An attacker could possibly use this issue to cause a denial of service. This issue only     affected Ubuntu 20.04 LTS and Ubuntu 22.04 LTS. (CVE-2024-27355)

Tenable has extracted the preceding description block directly from the Ubuntu 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 Debian 10 host has a package installed that is affected by multiple vulnerabilities as referenced in the dla-3750 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-3750-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                       Guilhem Moulin     March 05, 2024                                https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : php-phpseclib     Version        : 2.0.30-2~deb10u3     CVE ID         : CVE-2024-27354 CVE-2024-27355

    Security issues were discovered in php-phpseclib, a PHP library for     arbitrary-precision integer arithmetic, which could lead to Denial of     Service.

    CVE-2024-27354

        An attacker can construct a malformed certificate containing an         extremely large prime to cause a denial of service (CPU consumption         for an `isPrime` primality check).

        This issue was introduced when attempting to fix CVE-2023-27560.

    CVE-2024-27355

        When processing the ASN.1 object identifier of a certificate, a sub         identifier may be provided that leads to a denial of service (CPU         consumption for `decodeOID`).

    For Debian 10 buster, these problems have been fixed in version     2.0.30-2~deb10u3.

    We recommend that you upgrade your php-phpseclib packages.

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

    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: PGP signature

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 Debian 10 host has a package installed that is affected by multiple vulnerabilities as referenced in the dla-3749 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-3749-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                       Guilhem Moulin     March 05, 2024                                https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : phpseclib     Version        : 1.0.19-3~deb10u3     CVE ID         : CVE-2024-27354 CVE-2024-27355

    Security issues were discovered in phpseclib, a PHP library for     arbitrary-precision integer arithmetic, which could lead to Denial of     Service.

    CVE-2024-27354

        An attacker can construct a malformed certificate containing an         extremely large prime to cause a denial of service (CPU consumption         for an `isPrime` primality check).

        This issue was introduced when attempting to fix CVE-2023-27560.

    CVE-2024-27355

        When processing the ASN.1 object identifier of a certificate, a sub         identifier may be provided that leads to a denial of service (CPU         consumption for `decodeOID`).

    For Debian 10 buster, these problems have been fixed in version     1.0.19-3~deb10u3.

    We recommend that you upgrade your phpseclib packages.

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

    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: PGP signature

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
325133	Debian dla-4670 : php-phpseclib - security update	Nessus	Debian Local Security Checks	high
441523	SCA: security update for phpseclib/phpseclib (GHSA-f2qx-66wf-wvvx)	Tenable Cloud Security	SCA Checks	high
441523	SCA: security update for phpseclib/phpseclib (GHSA-f2qx-66wf-wvvx)	Tenable Self-Hosted Container Security	SCA Checks	high
233753	Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS : phpseclib vulnerabilities (USN-7404-1)	Nessus	Ubuntu Local Security Checks	high
191553	Debian dla-3750 : php-phpseclib - security update	Nessus	Debian Local Security Checks	high
191552	Debian dla-3749 : php-seclib - security update	Nessus	Debian Local Security Checks	high

Detections

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CVE-2024-27355

high

Tenable Plugins

high

high

high

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high

high