CVE-2021-3521

rpm: RPM does not require subkeys to have a valid binding signature

Published Aug 22, 2022 CVSS 3.1 · 4.7 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2021-26837 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.
History

No history.

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Aug 3, 2024, 5:01 PM
Reserved
Apr 28, 2021, 12:00 AM
Status
Modified
Published
Aug 22, 2022, 3:15 PM
Modified
Jun 17, 2026, 4:05 AM
Severity
Moderate
Public date
Sep 28, 2021, 12:00 AM