TencentOS Server 3: libtar (TSSA-2023:0136)

critical Nessus Plugin ID 239260

Synopsis

The remote TencentOS Server 3 host is missing one or more security updates.

Description

The version of Tencent Linux installed on the remote TencentOS Server 3 host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the TSSA-2023:0136 advisory.

Package updates are available for TencentOS Server 3 that fix the following vulnerabilities:

CVE-2021-33640:
After tar_close(), libtar.c releases the memory pointed to by pointer t. After tar_close() is called in the list() function, it continues to use pointer t: free_longlink_longname(t->th_buf) . As a result, the released memory is used (use-after-free).
CVE-2021-33645:
A flaw was found in libtar. This security vulnerability occurs because the th_read() function in libtar doesnt free a variable t->th_buf.gnu_longlink after allocating memory, which may cause a memory leak.

CVE-2021-33646:
A flaw was found in libtar. This security vulnerability occurs because the th_read() function in libtar doesnt free a variable t->th_buf.gnu_longname after allocating memory, which may cause a memory leak.

CVE-2021-33643:
A flaw was found in libtar. This flaw allows an attacker who submits a crafted tar file with the size in the header struct being 0 to trigger a calling of malloc(0) for a variable gnu_longlink, causing an out- of-bounds read.

CVE-2021-33644:
A flaw was found in libtar. This flaw allows an attacker who submits a crafted tar file with size in header struct being 0 to trigger a calling of malloc(0) for a variable gnu_longname, causing an out-of- bounds read.

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.

Plugin Details

Severity: Critical

ID: 239260

File Name: tencentos_TSSA_2023_0136.nasl

Version: 1.2

Type: local

Family: Tencent Local Security Checks

Published: 6/16/2025

Updated: 11/20/2025

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.0

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

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

CVSS Score Source: CVE-2021-33640

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:tencent:tencentos_server:libtar, cpe:/o:tencent:tencentos_server:3

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

Exploit Ease: No known exploits are available

Patch Publication Date: 7/13/2023

Vulnerability Publication Date: 7/13/2023

Reference Information

CVE: CVE-2021-33640, CVE-2021-33643, CVE-2021-33644, CVE-2021-33645, CVE-2021-33646

Detections

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