RHSA-2021:4034 - Security Advisory

Topic

An update for binutils is now available for Red Hat Enterprise Linux 7.7 Advanced Update Support, Red Hat Enterprise Linux 7.7 Telco Extended Update Support, and Red Hat Enterprise Linux 7.7 Update Services for SAP Solutions.

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 binutils packages provide a collection of binary utilities for the manipulation of object code in various object file formats. It includes the ar, as, gprof, ld, nm, objcopy, objdump, ranlib, readelf, size, strings, strip, and addr2line utilities.

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 binutils in order to facilitate detection of BiDi Unicode characters:

Tools which display names or strings (readelf, strings, nm, objdump) have a new command line option --unicode / -U which controls how Unicode characters are handled.

Using "--unicode=default" will treat them as normal for the tool. This is the default behaviour when --unicode option is not used.
Using "--unicode=locale" will display them according to the current locale.
Using "--unicode=hex" will display them as hex byte values.
Using "--unicode=escape" will display them as Unicode escape sequences.
Using "--unicode=highlight" will display them as Unicode escape sequences highlighted in red, if supported by the output device.

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.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.7 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.7 x86_64

Fixes

• BZ - 2005819 - CVE-2021-42574 Developer environment: Unicode's bidirectional (BiDi) override characters can cause trojan source attacks

CVEs

• CVE-2021-42574

References

• https://access.redhat.com/security/updates/classification/#moderate
• https://access.redhat.com/security/vulnerabilities/RHSB-2021-007