CVE-2021-3521
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.
Does this matter?
Lower severity and a low EPSS score (0.32%). Track it; it rarely justifies an emergency change on its own.
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
- 4.7 MEDIUMCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
- EPSS
- 0.32% probability · 25th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-347
- Affected
- rpm/rpm
- Source
- secalert@redhat.com
References
- https://access.redhat.com/security/cve/CVE-2021-3521Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1941098Issue Tracking, Patch, Third Party Advisory
- https://github.com/rpm-software-management/rpm/commit/bd36c5dc9fb6d90c46fbfed8c2d67516fc571ec8Patch, Third Party Advisory
- https://github.com/rpm-software-management/rpm/pull/1795/Patch, Third Party Advisory
- https://security.gentoo.org/glsa/202210-22Third Party Advisory
- https://access.redhat.com/security/cve/CVE-2021-3521Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1941098Issue Tracking, Patch, Third Party Advisory
- https://github.com/rpm-software-management/rpm/commit/bd36c5dc9fb6d90c46fbfed8c2d67516fc571ec8Patch, Third Party Advisory
- https://github.com/rpm-software-management/rpm/pull/1795/Patch, Third Party Advisory
- https://security.gentoo.org/glsa/202210-22Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.