RHSA-2021:4585 — Security Advisory
Red Hat Security Advisory: gcc-toolset-10-gcc security update
Severity
ModerateRed Hat Product Security
Products
Official CSAF product identity
Published · November 10, 2021
Updated · August 7, 2026
Topic
An update for gcc-toolset-10-gcc is now available for Red Hat Enterprise Linux 8.
Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.
Description
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.