Detections
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TencentOS Server 4: freerdp (TSSA-2026:0039)

high Nessus Plugin ID 297109

Synopsis

The remote TencentOS Server 4 host is missing one or more security updates.

Description

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the TSSA-2026:0039 advisory.

 Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

 CVE-2026-23883:
 FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, `xf_Pointer_New` frees `cursorPixels` on failure, then `pointer_free` calls `xf_Pointer_Free` and frees it again, triggering ASan UAF. A malicious server can trigger a clientside use after free, causing a crash (DoS) and potential heap corruption with codeexecution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

 CVE-2026-23534:
 FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, a client-side heap buffer overflow occurs in the ClearCodec bands decode path when crafted band coordinates allow writes past the end of the destination surface buffer. A malicious server can trigger a clientside heap buffer overflow, causing a crash (DoS) and potential heap corruption with codeexecution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

 CVE-2026-23532:
 FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, a client-side heap buffer overflow occurs in the FreeRDP clients `gdi_SurfaceToSurface` path due to a mismatch between destination rectangle clamping and the actual copy size. A malicious server can trigger a clientside heap buffer overflow, causing a crash (DoS) and potential heap corruption with codeexecution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

 CVE-2026-23531:
 FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, in ClearCodec, when `glyphData` is present, `clear_decompress` calls `freerdp_image_copy_no_overlap` without validating the destination rectangle, allowing an out-of-bounds read/write via crafted RDPGFX surface updates. A malicious server can trigger a clientside heap buffer overflow, causing a crash (DoS) and potential heap corruption with codeexecution risk depending on allocator behavior and surrounding heap layout.
 Version 3.21.0 contains a patch for the issue.

 CVE-2026-23530:
 FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0,`freerdp_bitmap_decompress_planar` does not validate `nSrcWidth`/`nSrcHeight` against `planar->maxWidth`/`maxHeight` before RLE decode. A malicious server can trigger a clientside heap buffer overflow, causing a crash (DoS) and potential heap corruption with codeexecution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

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

Solution

Update the affected packages.

See Also

https://mirrors.tencent.com/tlinux/errata/tssa-20260039.xml

Plugin Details

Severity: High

ID: 297109

File Name: tencentos_TSSA_2026_0039.nasl

Version: 1.1

Type: local

Published: 1/29/2026

Updated: 1/29/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.8

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

CVSS Score Source: CVE-2026-23883

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

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

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

CVSS v4

Risk Factor: High

Base Score: 8.7

Threat Score: 7.7

Threat Vector: CVSS:4.0/E:P

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

Vulnerability Information

CPE: p-cpe:/a:tencent:tencentos_server:freerdp, cpe:/o:tencent:tencentos_server:4

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/etc/os-release, Host/TencentOS/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 1/28/2026

Vulnerability Publication Date: 1/19/2026

Reference Information

CVE: CVE-2026-23530, CVE-2026-23531, CVE-2026-23532, CVE-2026-23534, CVE-2026-23883