A flaw was found in the key export functionality of libssh. The issue occurs in the internal function responsible for converting cryptographic keys into serialized formats. During error handling, a memory structure is freed but not cleared, leading to a potential double free issue if an additional failure occurs later in the function. This condition may result in heap corruption or application instability in low-memory scenarios, posing a risk to system reliability where key export operations are performed.

The version of libssh installed on the remote CBL Mariner 2.0 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the CVE-2025-5351 advisory.

  - A flaw was found in the key export functionality of libssh. The issue occurs in the internal function     responsible for converting cryptographic keys into serialized formats. During error handling, a memory     structure is freed but not cleared, leading to a potential double free issue if an additional failure     occurs later in the function. This condition May result in heap corruption or application instability in     low-memory scenarios, posing a risk to system reliability where key export operations are performed.
    (CVE-2025-5351)

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 libssh 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-2025-5351 advisory.

  - A flaw was found in the key export functionality of libssh. The issue occurs in the internal function     responsible for converting cryptographic keys into serialized formats. During error handling, a memory     structure is freed but not cleared, leading to a potential double free issue if an additional failure     occurs later in the function. This condition May result in heap corruption or application instability in     low-memory scenarios, posing a risk to system reliability where key export operations are performed.
    (CVE-2025-5351)

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

The remote Ubuntu 22.04 LTS / 24.04 LTS / 24.10 / 25.04 host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-7619-1 advisory.

    Ronald Crane discovered that libssh incorrectly handled certain base64 conversions. An attacker could use     this issue to cause libssh to crash, resulting in a denial of service, or possibly execute arbitrary code.
    (CVE-2025-4877)

    Ronald Crane discovered that libssh incorrectly handled the privatekey_from_file() function. An attacker     could use this issue to cause libssh to crash, resulting in a denial of service, or possibly execute     arbitrary code. (CVE-2025-4878)

    Ronald Crane discovered that libssh incorrectly handled certain memory operations in the sftp server. An     attacker could possibly use this issue to cause libssh to crash, resulting in a denial of service.
    (CVE-2025-5318, CVE-2025-5449)

    Ronald Crane discovered that libssh incorrectly handled exporting keys. An attacker could possibly use     this issue to cause libssh to crash, resulting in a denial of service. This issue only affected Ubuntu     24.04 LTS, Ubuntu 24.10, and Ubuntu 25.04. (CVE-2025-5351)

    Ronald Crane discovered that libssh incorrectly handled the ssh_kdf() function. An attacker could use this     issue to cause libssh to crash, resulting in a denial of service, or possibly execute arbitrary code.
    (CVE-2025-5372)

    Ronald Crane discovered that libssh incorrectly handled the ChaCha20 cipher. An attacker could possibly     use this issue to cause libssh to use partially initialized cypher content. This issue only affected     Ubuntu 24.04 LTS, Ubuntu 24.10, and Ubuntu 25.04. (CVE-2025-5987)

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 version of libssh installed on the remote host is prior to 0.11.2. It is, therefore, affected by multiple vulnerabilities as referenced in the SSA:2025-175-01 advisory.

    New libssh packages are available for Slackware 15.0 and -current to fix security issues.

Tenable has extracted the preceding description block directly from the libssh 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
242392	CBL Mariner 2.0 Security Update: libssh (CVE-2025-5351)	Nessus	MarinerOS Local Security Checks	medium
242385	Azure Linux 3.0 Security Update: libssh (CVE-2025-5351)	Nessus	Azure Linux Local Security Checks	medium
241506	Ubuntu 22.04 LTS / 24.04 LTS / 24.10 / 25.04 : libssh vulnerabilities (USN-7619-1)	Nessus	Ubuntu Local Security Checks	medium
240488	Slackware Linux 15.0 / current libssh Multiple Vulnerabilities (SSA:2025-175-01)	Nessus	Slackware Local Security Checks	medium

Detections

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CVE-2025-5351

medium

Tenable Plugins

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medium

medium

medium