CVE-2020-6096

NameCVE-2020-6096
DescriptionAn exploitable signed comparison vulnerability exists in the ARMv7 memcpy() implementation of GNU glibc 2.30.9000. Calling memcpy() (on ARMv7 targets that utilize the GNU glibc implementation) with a negative value for the 'num' parameter results in a signed comparison vulnerability. If an attacker underflows the 'num' parameter to memcpy(), this vulnerability could lead to undefined behavior such as writing to out-of-bounds memory and potentially remote code execution. Furthermore, this memcpy() implementation allows for program execution to continue in scenarios where a segmentation fault or crash should have occurred. The dangers occur in that subsequent execution and iterations of this code will be executed with this corrupted data.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-3152-1
Debian Bugs961452

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
glibc (PTS)buster2.28-10+deb10u1vulnerable (unimportant)
buster (security)2.28-10+deb10u2fixed
bullseye2.31-13+deb11u8fixed
bullseye (security)2.31-13+deb11u7fixed
bookworm, bookworm (security)2.36-9+deb12u4fixed
trixie2.37-15fixed
sid2.37-15.1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
glibcsourcejessie(not affected)
glibcsourcebuster2.28-10+deb10u2DLA-3152-1
glibcsource(unstable)2.31-2low961452

Notes

[jessie] - glibc <not-affected> (Vulnerable code not present)
https://sourceware.org/bugzilla/show_bug.cgi?id=25620
https://talosintelligence.com/vulnerability_reports/TALOS-2020-1019
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=beea361050728138b82c57dda0c4810402d342b9
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=79a4fa341b8a89cb03f84564fd72abaa1a2db394

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