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Vulnerability record · CVE-2021-3521 · published 22 August 2022

CVE-2021-3521: Rpm improper verification of cryptographic signature vulnerability

Rpm · Rpm

There is a flaw in RPM's signature functionality. OpenPGP subkeys are associated with a primary key via a "binding signature." RPM does not check the binding signature of subkeys prior to importing them. If an attacker is able to add or socially engineer another party to add a malicious subkey to a legitimate public key, RPM could wrongly trust a malicious signature. The greatest impact of this flaw is to data integrity. To exploit this flaw, an attacker must either compromise an RPM repository or convince an administrator to install an untrusted RPM or public key. It is strongly recommended to only use RPMs and public keys from trusted sources.

4.7 CVSS 3.1 Medium EPSS 0.33% · top 76.0% CWE-347 · Improper verification of cryptographic signature
4.7CVSS 3.1 base score
0.33%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
10References
17 Jun 2026Last modified by NVD

Description

There is a flaw in RPM's signature functionality. OpenPGP subkeys are associated with a primary key via a "binding signature." RPM does not check the binding signature of subkeys prior to importing them. If an attacker is able to add or socially engineer another party to add a malicious subkey to a legitimate public key, RPM could wrongly trust a malicious signature. The greatest impact of this flaw is to data integrity. To exploit this flaw, an attacker must either compromise an RPM repository or convince an administrator to install an untrusted RPM or public key. It is strongly recommended to only use RPMs and public keys from trusted sources.

CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://access.redhat.com/security/cve/CVE-2021-3521 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1941098 Issue TrackingPatchThird Party Advisory
https://github.com/rpm-software-management/rpm/commit/bd36c5dc9fb6d90c46fbfed8c2d67516fc571ec8 PatchThird Party Advisory
https://github.com/rpm-software-management/rpm/pull/1795/ PatchThird Party Advisory
https://security.gentoo.org/glsa/202210-22 Third Party Advisory
https://access.redhat.com/security/cve/CVE-2021-3521 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1941098 Issue TrackingPatchThird Party Advisory
https://github.com/rpm-software-management/rpm/commit/bd36c5dc9fb6d90c46fbfed8c2d67516fc571ec8 PatchThird Party Advisory
https://github.com/rpm-software-management/rpm/pull/1795/ PatchThird Party Advisory
https://security.gentoo.org/glsa/202210-22 Third Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2014-8118Rpm vulnerabilityInteger overflow in RPM 4.12 and earlier allows remote attackers to execute arbitrary code via a crafted CPIO header in the payload section of an RPM…EPSS 7.6%9.3CVE-2011-3378Rpm code injection vulnerabilityRPM 4.4.x through 4.9.x, probably before 4.9.1.2, allows remote attackers to cause a denial of service (memory corruption) and possibly execute arbit…EPSS 5.9%7.8CVE-2017-7500Rpm link following vulnerabilityIt was found that rpm did not properly handle RPM installations when a destination path was a symbolic link to a directory, possibly changing ownersh…EPSS 0.41%7.8CVE-2017-7501Rpm link following vulnerabilityIt was found that versions of rpm before 4.13.0.2 use temporary files with predictable names when installing an RPM. An attacker with ability to writ…EPSS 0.39%7.6CVE-2013-6435Rpm injection vulnerabilityRace condition in RPM 4.11.1 and earlier allows remote attackers to execute arbitrary code via a crafted RPM file whose installation extracts the con…EPSS 7.6%7.2CVE-2010-2198Rpm permissions and access controls vulnerabilitylib/fsm.c in RPM 4.8.0 and earlier does not properly reset the metadata of an executable file during replacement of the file in an RPM package upgrad…EPSS 0.36%7.2CVE-2010-2059Rpm permissions and access controls vulnerabilitylib/fsm.c in RPM 4.8.0 and unspecified 4.7.x and 4.6.x versions, and RPM before 4.4.3, does not properly reset the metadata of an executable file dur…EPSS 0.40%7.2CVE-2010-2199Rpm permissions and access controls vulnerabilitylib/fsm.c in RPM 4.8.0 and earlier does not properly reset the metadata of an executable file during replacement of the file in an RPM package upgrad…EPSS 0.31%

Source: NIST National Vulnerability Database (record CVE-2021-3521), CISA KEV, FIRST EPSS (scores of 2026-10-17). This page is refreshed as NVD updates the record.