CVE-2021-20266

Severity: medium (CVSS 4.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-04-30 · updated 2026-06-17
Weakness: CWE-125

Description

A flaw was found in RPM's hdrblobInit() in lib/header.c. This flaw allows an attacker who can modify the rpmdb to cause an out-of-bounds read. The highest threat from this vulnerability is to system availability.

Affected products

Fedoraproject Fedora: 33, 34
RPM: before 4.16.1.3 — fixed in 4.16.1.3

How to fix

Upgrade to a fixed version: RPM 4.16.1.3. Check the vendor advisory for mitigations.

References

https://bugzilla.redhat.com/show_bug.cgi?id=1927741
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TMGXO3W6DHPO62GJ4VVF5DEUX5DRUR5K/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VHRPNBCRPDJHHQE3MBPSZK4H7X2IM7AC/
https://security.gentoo.org/glsa/202107-43
https://bugzilla.redhat.com/show_bug.cgi?id=1927741
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TMGXO3W6DHPO62GJ4VVF5DEUX5DRUR5K/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VHRPNBCRPDJHHQE3MBPSZK4H7X2IM7AC/
https://security.gentoo.org/glsa/202107-43

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