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EulerOS Virtualization 2.11.0 : libssh (EulerOS-SA-2026-3520)

medium Nessus Plugin ID 347135

Synopsis

The remote EulerOS Virtualization host is missing multiple security updates.

Description

According to the versions of the libssh package installed, the EulerOS Virtualization 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 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)

 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)

 The API function `ssh_get_hexa()` is vulnerable, when 0-lenght input is provided to this function. This function is used internally in `ssh_get_fingerprint_hash()` and `ssh_print_hexa()` (deprecated),which is vulnerable to the same input (length is provided by the calling application).The function is also used internally in the gssapi code for logging the OIDs received by the server during GSSAPI authentication.
 This could be triggered remotely, when the server allows GSSAPI authentication and logging verbosity is set at least to SSH_LOG_PACKET (3). This could cause self-DoS of the per-connection daemon process.(CVE-2026-0966)

 A flaw was found in libssh in which a malicious SFTP (SSH File Transfer Protocol) server can exploit this by sending a malformed 'longname' field within an `SSH_FXP_NAME` message during a file listing operation.
 This missing null check can lead to reading beyond allocated memory on the heap. This can cause unexpected behavior or lead to a denial of service (DoS) due to application crashes.(CVE-2026-0968)

 A flaw was found in libssh where it can attempt to open arbitrary files during configuration parsing. A local attacker can exploit this by providing a malicious configuration file or when the system is misconfigured. This vulnerability could lead to a Denial of Service (DoS) by causing the system to try and access dangerous files, such as block devices or large system files, which can disrupt normal operations.(CVE-2026-0965)

 A malicious SCP server can send unexpected paths that could make the client application override local files outside of working directory.This could be misused to create malicious executable or configuration files and make the user execute them under specific consequences.This is the same issue as in OpenSSH, tracked as CVE-2019-6111.(CVE-2026-0964)

 A flaw was found in libssh. A remote attacker, by controlling client configuration files or known_hosts files, could craft specific hostnames that when processed by the `match_pattern()` function can lead to inefficient regular expression backtracking. This can cause timeouts and resource exhaustion, resulting in a Denial of Service (DoS) for the client.(CVE-2026-0967)

 A weakness has been identified in libssh up to 0.11.3. The impacted element is the function sftp_extensions_get_name/sftp_extensions_get_data of the file src/sftp.c of the component SFTP Extension Name Handler. Executing a manipulation of the argument idx can lead to out-of-bounds read. The attack may be performed from remote. Upgrading to version 0.11.4 and 0.12.0 is sufficient to resolve this issue. This patch is called 855a0853ad3abd4a6cd85ce06fce6d8d4c7a0b60. You should upgrade the affected component.(CVE-2026-3731)

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

Solution

Update the affected libssh packages.

See Also

http://www.nessus.org/u?cc29560f

Plugin Details

Severity: Medium

ID: 347135

File Name: EulerOS_SA-2026-3520.nasl

Version: 1.1

Type: Local

Published: 9/18/2026

Updated: 9/18/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.3

Percentile: 96.81

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2026-3731

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS Score Source: CVE-2025-5372

CVSS v4

Risk Factor: Medium

Base Score: 6.9

Threat Score: 2.7

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Vulnerability Information

CPE: cpe:/o:huawei:euleros:uvp:2.11.0, p-cpe:/a:huawei:euleros:libssh

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/EulerOS/release, Host/EulerOS/rpm-list, Host/EulerOS/uvp_version

Exploit Ease: No known exploits are available

Patch Publication Date: 9/16/2026

Vulnerability Publication Date: 2/12/2025

Reference Information

CVE: CVE-2025-4877, CVE-2025-4878, CVE-2025-5318, CVE-2025-5372, CVE-2025-8114, CVE-2025-8277, CVE-2026-0964, CVE-2026-0965, CVE-2026-0966, CVE-2026-0967, CVE-2026-0968, CVE-2026-3731

IAVA: 2025-A-0462-S, 2025-A-0692-S, 2026-A-0166-S