CVE-2021-4090

NameCVE-2021-4090
DescriptionAn out-of-bounds (OOB) memory write flaw was found in the NFSD in the Linux kernel. Missing sanity may lead to a write beyond bmval[bmlen-1] in nfsd4_decode_bitmap4 in fs/nfsd/nfs4xdr.c. In this flaw, a local attacker with user privilege may gain access to out-of-bounds memory, leading to a system integrity and confidentiality threat.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)buster4.19.249-2fixed
buster (security)4.19.304-1fixed
bullseye5.10.209-2fixed
bullseye (security)5.10.205-2fixed
bookworm6.1.76-1fixed
bookworm (security)6.1.69-1fixed
trixie6.6.15-2fixed
sid6.7.9-2fixed

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsourcestretch(not affected)
linuxsourcebuster(not affected)
linuxsourcebullseye(not affected)
linuxsource(unstable)5.15.5-1

Notes

[bullseye] - linux <not-affected> (Vulnerable code introduced later)
[buster] - linux <not-affected> (Vulnerable code introduced later)
[stretch] - linux <not-affected> (Vulnerable code introduced later)
https://bugzilla.redhat.com/show_bug.cgi?id=2025101
https://git.kernel.org/linus/c0019b7db1d7ac62c711cda6b357a659d46428fe (5.16-rc2)

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