PT-2021-6514 · Tcl+3 · Tcl+3

Salmonx · Published 2021-05-07 · Updated 2025-08-12 · CVE-2021-35331

Positive Technologies (AI Summary)

CVSS v2.0

10

High

Base vector

AV:N/AC:L/Au:N/C:C/I:C/A:C

Name of the Vulnerable Software and Affected Versions Tcl version 8.6.11

Description A format string vulnerability in the nmakehlp.c component of the Tcl programming language may allow code execution via a crafted file. This issue is related to insufficient processing of format strings, which could enable a remote attacker to access confidential data, compromise its integrity, and cause a denial of service using a specially crafted file. Note that multiple third parties dispute the significance of this finding.

Recommendations For Tcl version 8.6.11, as a temporary workaround, consider restricting access to the nmakehlp.c component until a patch is available. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Use of Externally-Controlled Format String

Weakness Enumeration

CWE-134

Related Identifiers

ALT-PU-2021-3242

ALT-PU-2024-9046

BDU:2022-01774

CVE-2021-35331

ECHO-CD9D-2394-E10E

OESA-2022-1720

ROSA-SA-2024-2541

SUSE-FU-2022:0484-1

SUSE-FU-2022:0868-1

Affected Products

Alt Linux

Astra Linux

Debian

Tcl

References · 34

• 🔥 https://core.tcl-lang.org/tcl/info/bad6cc213dfe8280 · Exploit
• 🔥 https://sqlite.org/forum/info/7dcd751996c93ec9 · Exploit
• 🔥 https://core.tcl-lang.org/tcl/info/28ef6c0c741408a2 · Exploit
• https://github.com/tcltk/tcl/commit/4705dbdde2f32ff90420765cd93e7ac71d81a222 · Patch
• https://osv.dev/vulnerability/SUSE-FU-2022:0484-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-35331 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2021-35331 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-FU-2022:0868-1 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-35331 · Vendor Advisory
• https://osv.dev/vulnerability/OESA-2022-1720 · Vendor Advisory
• https://wiki.astralinux.ru/astra-linux-se17-bulletin-2023-0303SE17MD · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-35331 · Vendor Advisory
• https://osv.dev/vulnerability/ROOT-OS-DEBIAN-12-CVE-2021-35331 · Vendor Advisory
• https://wiki.astralinux.ru/astra-linux-se47-bulletin-2023-0316SE47MD · Vendor Advisory
• https://bdu.fstec.ru/vul/2022-01774 · Security Note