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🛡️ RLSA-2021:4586 — gcc-toolset-11-gcc (CVE-2021-42574)

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Moderate: gcc-toolset-11-gcc security update

The gcc packages provide compilers for C, C++, Java, Fortran, Objective C, and Ada 95 GNU, as well as related support libraries.

Security Fix(es):

  • Developer environment: Unicode's bidirectional (BiDi) override characters can cause trojan source attacks (CVE-2021-42574)

The following changes were introduced in gcc in order to facilitate detection of BiDi Unicode characters:

This update implements a new warning option -Wbidirectional to warn about possibly dangerous bidirectional characters.

There are three levels of warning supported by gcc:

"-Wbidirectional=unpaired", which warns about improperly terminated BiDi contexts. (This is the default.)

"-Wbidirectional=none", which turns the warning off.

"-Wbidirectional=any", which warns about any use of bidirectional characters.

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is high, an attacker needs low-level privileges on the target. No user interaction is required. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality high, integrity high, availability high.

Affected software

RLSA-2021:4586 is recorded against 1 package.

  • gcc-toolset-11-gcc (fixed in 0:11.2.1-1.2.el8_5)

Timeline and source

Published on 10 November 2021 and last revised on 4 February 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

errata.rockylinux.org (Advisory)
bugzilla.redhat.com (Report)

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2021-11-10
Updated 2026-08-20
Modified 2026-02-04
Fix URL N/A

Affected Packages

Software From version Fixed in
gcc-toolset-11-gcc — 0:11.2.1-1.2.el8_5

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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