A vulnerability was found in libssh, where an uninitialized variable exists under certain conditions in the privatekey_from_file() function. This flaw can be triggered if the file specified by the filename doesn't exist and may lead to possible signing failures or heap corruption.

According to the versions of the libssh package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

    There's a vulnerability in the libssh package where when a libssh consumer passes in an unexpectedly large     input buffer to ssh_get_fingerprint_hash() function. In such cases the bin_to_base64() function can     experience an integer overflow leading to a memory under allocation, when that happens it's possible that     the program perform out of bounds write leading to a heap corruption.
    This issue affects only 32-bits builds of libssh.(CVE-2025-4877)

    A vulnerability was found in libssh, where an uninitialized variable exists under certain conditions in     the privatekey_from_file() function. This flaw can be triggered if the file specified by the filename     doesn't exist and may lead to possible signing failures or heap corruption.(CVE-2025-4878)

    A flaw was found in libssh, a library that implements the SSH protocol. When calculating the session ID     during the key exchange (KEX) process, an allocation failure in cryptographic functions may lead to a NULL     pointer dereference. This issue can cause the client or server to crash.(CVE-2025-8114)

    A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends     incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually     exhaust system memory. This issue can lead to crashes on the client side, particularly when using     libgcrypt, which impacts application stability and availability.(CVE-2025-8277)

Tenable has extracted the preceding description block directly from the EulerOS 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.

The remote Debian 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4385 advisory.

    - -------------------------------------------------------------------------     Debian LTS Advisory DLA-4385-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/               Emilio Pozuelo Monfort     November 27, 2025                             https://wiki.debian.org/LTS
    - -------------------------------------------------------------------------

    Package        : libssh     Version        : 0.9.8-0+deb11u2     CVE ID         : CVE-2025-4877 CVE-2025-4878 CVE-2025-5318 CVE-2025-5372                      CVE-2025-8114 CVE-2025-8277     Debian Bug     : 1108407 1109860 1114859

    Several vulnerabilities have been found in libssh, a tiny C SSH library.

    CVE-2025-4877

        Ronald Crane found that bin_to_base64() could experience an integer         overflow and subsequent under allocation, leading to an out of         bounds write on 32-bit builds.

    CVE-2025-4878

        Ronald Crane found that privatekey_from_file() used an uninitialized         variable under certain conditions, which could lead to signing         failure, use-after-free or memory corruption.

    CVE-2025-5318

        Ronald Crane found that sftp_handle() had an incorrect check, which         could lead to an out of bounds read.

    CVE-2025-5372

        Ronald Crane found that ssh_kdf() returned a success code on         certain failures, which could lead to use of uninitialized         cryptographic keys and failing to encrypt/decrypt following         communication.

    CVE-2025-8114

        Philippe Antoine found a null pointer dereference issue when libssh         calculates the session id for the key exchange (KEX) process and an         error happens when allocating memory using cryptographic functions,         leading to a crash.

    CVE-2025-8277

        Francesco Rollo a memory leak during the KEX process when a client         sets the `first_kex_packet_follows` flag in the KEXINIT message and         repeatedly makes incorrect KEX guesses.

    For Debian 11 bullseye, these problems have been fixed in version     0.9.8-0+deb11u2.

    We recommend that you upgrade your libssh packages.

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

    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.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2025-990958 advisory.

    A vulnerability was found in libssh, where an uninitialized variable exists under certain conditions in     the privatekey_from_file() function. This flaw can be triggered if the file specified by the filename     doesn't exist and may lead to possible signing failures or heap corruption.

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

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

According to the versions of the libssh package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

    A flaw was found in libssh versions built with OpenSSL versions older than 3.0, specifically in the     ssh_kdf() function responsible for key derivation. Due to inconsistent interpretation of return values     where OpenSSL uses 0 to indicate failure and libssh uses 0 for successthe function may mistakenly     return a success status even when key derivation fails. This results in uninitialized cryptographic key     buffers being used in subsequent communication, potentially compromising SSH sessions' confidentiality,     integrity, and availability.(CVE-2025-5372)

    A flaw was found in libssh, a library that implements the SSH protocol. When calculating the session ID     during the key exchange (KEX) process, an allocation failure in cryptographic functions may lead to a NULL     pointer dereference. This issue can cause the client or server to crash.(CVE-2025-8114)

    There's a vulnerability in the libssh package where when a libssh consumer passes in an unexpectedly large     input buffer to ssh_get_fingerprint_hash() function. In such cases the bin_to_base64() function can     experience an integer overflow leading to a memory under allocation, when that happens it's possible that     the program perform out of bounds write leading to a heap corruption.
    This issue affects only 32-bits builds of libssh.(CVE-2025-4877)

    A vulnerability was found in libssh, where an uninitialized variable exists under certain conditions in     the privatekey_from_file() function. This flaw can be triggered if the file specified by the filename     doesn't exist and may lead to possible signing failures or heap corruption.(CVE-2025-4878)

Tenable has extracted the preceding description block directly from the EulerOS 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.

According to the versions of the libssh package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

    There's a vulnerability in the libssh package where when a libssh consumer passes in an unexpectedly large     input buffer to ssh_get_fingerprint_hash() function. In such cases the bin_to_base64() function can     experience an integer overflow leading to a memory under allocation, when that happens it's possible that     the program perform out of bounds write leading to a heap corruption.
    This issue affects only 32-bits builds of libssh.(CVE-2025-4877)

    A vulnerability was found in libssh, where an uninitialized variable exists under certain conditions in     the privatekey_from_file() function. This flaw can be triggered if the file specified by the filename     doesn't exist and may lead to possible signing failures or heap corruption.(CVE-2025-4878)

    A flaw was found in libssh versions built with OpenSSL versions older than 3.0, specifically in the     ssh_kdf() function responsible for key derivation. Due to inconsistent interpretation of return values     where OpenSSL uses 0 to indicate failure and libssh uses 0 for successthe function may mistakenly     return a success status even when key derivation fails. This results in uninitialized cryptographic key     buffers being used in subsequent communication, potentially compromising SSH sessions' confidentiality,     integrity, and availability.(CVE-2025-5372)

    A flaw was found in libssh, a library that implements the SSH protocol. When calculating the session ID     during the key exchange (KEX) process, an allocation failure in cryptographic functions may lead to a NULL     pointer dereference. This issue can cause the client or server to crash.(CVE-2025-8114)

Tenable has extracted the preceding description block directly from the EulerOS 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.

According to the versions of the libssh package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

    A vulnerability was found in libssh, where an uninitialized variable exists under certain conditions in     the privatekey_from_file() function. This flaw can be triggered if the file specified by the filename     doesn't exist and may lead to possible signing failures or heap corruption.(CVE-2025-4878)

    A flaw was found in the libssh library. An out-of-bounds read can be triggered in the sftp_handle function     due to an incorrect comparison check that permits the function to access memory beyond the valid handle     list and to return an invalid pointer, which is used in further processing. This vulnerability allows an     authenticated remote attacker to potentially read unintended memory regions, exposing sensitive     information or affect service behavior.(CVE-2025-5318)

Tenable has extracted the preceding description block directly from the EulerOS 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.

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2025-1155 advisory.

    The privatekey_from_file() uses an uninitialized variable under certainconditions, such as if the file     specified by the filename argument doesn'texist. This causes the code to return an invalid private key.

    This defect, in turn, might cause signing failure. The bug might also cause aUse-After-Free or corrupt the     heap.

    Note that privatekey_from_file() is a deprecated function and shouldn't be usedanymore! (CVE-2025-4878)

    An incorrect comparison check allows to read beyond bounds in the sftp_handle() in the sftp server     implementation. Thus an invalid pointer is returned as the handle and we try to continue using that.
    (CVE-2025-5318)

    pki_key_to_blob() can cause a double free on certain errors when using OpenSSL>= 3.0.  The function is     used by different other functions which allow toexport public or private keys to blobs or base64.

    The function is using the variable params without resetting it to NULL afterfree.  In case of low-memory     conditions when the allocation of string fails,the libssh calls the OSSL_PARAM_free() with the same     arguments, which willlikely crash. (CVE-2025-5351)

    If there is an error in initializing ChaCha20 cipher with OpenSSL, an invaliderror code is returned. This     can happen if there is an heap exhaustion.  Thiserror is not correctly detected and could allow libssh to     use partiallyinitialized cipher context.

    This is caused by the mismatch of return value meaning from OpenSSL and libssh,where OpenSSL error (rv=0)     aliases with SSH_OK (0) and is returned directlyfrom the function chacha20_poly1305_set_key(). This will     likely cause errorsomewhere down the road. (CVE-2025-5987)

Tenable has extracted the preceding description block directly from the tested product 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 libssh package has been released.

The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-7696-1 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)

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 SUSE Linux SLES12 host has a package installed that is affected by multiple vulnerabilities as referenced in the SUSE-SU-2025:02755-1 advisory.

    - CVE-2025-4877: Fixed write beyond bounds in binary to base64 conversion functions (bsc#1245309).
    - CVE-2025-4878: Fixed use of uninitialized variable in privatekey_from_file() (bsc#1245310).
    - CVE-2025-5318: Fixed likely read beyond bounds in sftp server handle management (bsc#1245311).

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.

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

  - A vulnerability was found in libssh, where an uninitialized variable exists under certain conditions in     the privatekey_from_file() function. This flaw can be triggered if the file specified by the filename     doesn't exist and may lead to possible signing failures or heap corruption. (CVE-2025-4878)

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

The remote Fedora 41 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2025-18e8506d3a advisory.

    New upstream release with security fixes for CVE-2025-4877, CVE-2025-4878, CVE-2025-5987, CVE-2025-5318,     CVE-2025-5351, CVE-2025-5372, CVE-2025-5449

    ----

    Automatic update for libssh-0.11.0-1.fc41.


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 SUSE Linux SLES12 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2025:02281-1 advisory.

    - CVE-2025-4877: Fixed write beyond bounds in binary to base64 conversion functions (bsc#1245309).
    - CVE-2025-4878: Fixed use of uninitialized variable in privatekey_from_file() (bsc#1245310).
    - CVE-2025-5318: Fixed likely read beyond bounds in sftp server handle management (bsc#1245311).
    - CVE-2025-5372: Fixed ssh_kdf() returns a success code on certain failures (bsc#1245314).

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.

The remote SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2025:02279-1 advisory.

    - CVE-2025-4877: Fixed write beyond bounds in binary to base64 conversion functions (bsc#1245309).
    - CVE-2025-4878: Fixed use of uninitialized variable in privatekey_from_file() (bsc#1245310).
    - CVE-2025-5318: Fixed likely read beyond bounds in sftp server handle management (bsc#1245311).
    - CVE-2025-5372: Fixed ssh_kdf() returns a success code on certain failures (bsc#1245314).

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.

The remote SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2025:02278-1 advisory.

    - CVE-2025-4877: Fixed write beyond bounds in binary to base64 conversion functions (bsc#1245309).
    - CVE-2025-4878: Fixed use of uninitialized variable in privatekey_from_file() (bsc#1245310).
    - CVE-2025-5318: Fixed likely read beyond bounds in sftp server handle management (bsc#1245311).
    - CVE-2025-5372: Fixed ssh_kdf() returns a success code on certain failures (bsc#1245314).

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.

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 remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 / openSUSE 15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2025:02229-1 advisory.

    - CVE-2025-5318: Fixed likely read beyond bounds in sftp server handle management (bsc#1245311).
    - CVE-2025-4877: Fixed write beyond bounds in binary to base64 conversion functions (bsc#1245309).
    - CVE-2025-4878: Fixed use of uninitialized variable in privatekey_from_file() (bsc#1245310).
    - CVE-2025-5372: Fixed cases where ssh_kdf() returns a success code on certain failures (bsc#1245314).

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.

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
278489	EulerOS 2.0 SP11 : libssh (EulerOS-SA-2025-2465)	Nessus	Huawei Local Security Checks	medium
278446	EulerOS 2.0 SP11 : libssh (EulerOS-SA-2025-2484)	Nessus	Huawei Local Security Checks	medium
277290	Debian dla-4385 : libssh-4 - security update	Nessus	Debian Local Security Checks	high
276652	Unity Linux 20.1050a / 20.1060a / 20.1070a Security Update: libssh (UTSA-2025-990958)	Nessus	Unity Linux Local Security Checks	low
274927	EulerOS 2.0 SP12 : libssh (EulerOS-SA-2025-2332)	Nessus	Huawei Local Security Checks	high
274919	EulerOS 2.0 SP10 : libssh (EulerOS-SA-2025-2420)	Nessus	Huawei Local Security Checks	high
274867	EulerOS 2.0 SP12 : libssh (EulerOS-SA-2025-2363)	Nessus	Huawei Local Security Checks	high
274860	EulerOS 2.0 SP10 : libssh (EulerOS-SA-2025-2392)	Nessus	Huawei Local Security Checks	high
271357	EulerOS 2.0 SP13 : libssh (EulerOS-SA-2025-2299)	Nessus	Huawei Local Security Checks	high
271353	EulerOS 2.0 SP13 : libssh (EulerOS-SA-2025-2267)	Nessus	Huawei Local Security Checks	high
261738	Amazon Linux 2023 : libssh, libssh-config, libssh-devel (ALAS2023-2025-1155)	Nessus	Amazon Linux Local Security Checks	high
260441	Photon OS 5.0: Libssh PHSA-2025-5.0-0597	Nessus	PhotonOS Local Security Checks	high
253441	Photon OS 4.0: Libssh PHSA-2025-4.0-0856	Nessus	PhotonOS Local Security Checks	high
252946	Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : libssh vulnerabilities (USN-7696-1)	Nessus	Ubuntu Local Security Checks	medium
249216	SUSE SLES12 Security Update : libssh (SUSE-SU-2025:02755-1)	Nessus	SuSE Local Security Checks	medium
245950	Linux Distros Unpatched Vulnerability : CVE-2025-4878	Nessus	Misc.	low
244363	Fedora 41 : libssh (2025-18e8506d3a)	Nessus	Fedora Local Security Checks	medium
242013	SUSE SLES12 Security Update : libssh (SUSE-SU-2025:02281-1)	Nessus	SuSE Local Security Checks	medium
241965	SUSE SLES15 Security Update : libssh (SUSE-SU-2025:02279-1)	Nessus	SuSE Local Security Checks	medium
241960	SUSE SLES15 Security Update : libssh (SUSE-SU-2025:02278-1)	Nessus	SuSE 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
241379	SUSE SLED15 / SLES15 / openSUSE 15 Security Update : libssh (SUSE-SU-2025:02229-1)	Nessus	SuSE Local Security Checks	medium
240488	Slackware Linux 15.0 / current libssh Multiple Vulnerabilities (SSA:2025-175-01)	Nessus	Slackware Local Security Checks	medium

Detections

Analytics

CVE-2025-4878

low

Tenable Plugins

medium

medium

high

low

high

high

high

high

high

high

high

high

high

medium

medium

low

medium

medium

medium

medium

medium

medium

medium