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OpenAdvisories
Medium ALSA-2021:4587 1 CVE

Moderate: gcc security update

Published Nov 10, 2021 · Updated Oct 29, 2026

Summary

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.

Fixed packages 12

ReleasePackageFixed in
AlmaLinux · 8 cpp 8.5.0-4.el8_5.alma
AlmaLinux · 8 gcc 8.5.0-4.el8_5.alma
AlmaLinux · 8 gcc-c++ 8.5.0-4.el8_5.alma
AlmaLinux · 8 gcc-gdb-plugin 8.5.0-4.el8_5.alma
AlmaLinux · 8 gcc-gfortran 8.5.0-4.el8_5.alma
AlmaLinux · 8 gcc-offload-nvptx 8.5.0-4.el8_5.alma
AlmaLinux · 8 gcc-plugin-devel 8.5.0-4.el8_5.alma
AlmaLinux · 8 libitm-devel 8.5.0-4.el8_5.alma
AlmaLinux · 8 libquadmath-devel 8.5.0-4.el8_5.alma
AlmaLinux · 8 libstdc++-devel 8.5.0-4.el8_5.alma
AlmaLinux · 8 libstdc++-docs 8.5.0-4.el8_5.alma
AlmaLinux · 8 libstdc++-static 8.5.0-4.el8_5.alma

Vulnerabilities 1

References

  • report
    https://vulners.com/cve/CVE-2021-42574