Improper signature verification in RPM
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Partial Red Hat: 6 fixed, 2 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-347.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | RPM | Fixed in rpm-4.18.0-beta1, rpm-4.18.0-alpha2, rpm-4.18.0-alpha1 . | — | No fix listed | CNA |
- RPM Vendor— Affected Fixed in rpm-4.18.0-beta1, rpm-4.18.0-alpha2, rpm-4.18.0-alpha1 . Fixed in — No fix listed CNA
Remediation
Red Hat 3 advisories
- RHSA-2022:0634 Released 2022-02-22 · Red Hat rating Moderaterpm security update
- Red Hat Enterprise Linux AppStream EUS (v. 8.2) rpm-build-4.14.2-40.el8_2
- Red Hat Enterprise Linux BaseOS EUS (v. 8.2) python3-rpm-4.14.2-40.el8_2, rpm-4.14.2-40.el8_2, rpm-apidocs-4.14.2-40.el8_2 +10
- RHSA-2022:0368 Released 2022-02-01 · Red Hat rating Moderaterpm security update
- Red Hat Enterprise Linux AppStream (v. 8) rpm-build-4.14.3-19.el8_5.2, rpm-plugin-fapolicyd-4.14.3-19.el8_5.2
- Red Hat Enterprise Linux BaseOS (v. 8) python3-rpm-4.14.3-19.el8_5.2, rpm-4.14.3-19.el8_5.2, rpm-apidocs-4.14.3-19.el8_5.2 +10
- RHSA-2022:0254 Released 2022-01-25 · Red Hat rating Moderaterpm security update
- Red Hat Enterprise Linux AppStream EUS (v.8.4) rpm-build-4.14.3-14.el8_4.2, rpm-plugin-fapolicyd-4.14.3-14.el8_4.2
- Red Hat Enterprise Linux BaseOS EUS (v.8.4) python3-rpm-4.14.3-14.el8_4.2, rpm-4.14.3-14.el8_4.2, rpm-apidocs-4.14.3-14.el8_4.2 +10
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
RPM — GLSA-202210-22
4 records Highest priority Priority LOW 4 LOW
Other records, highest priority first
- TI-2021-14394 Link following in RPMPriority LOW 30
- TI-2021-14393 Link following in RPMPriority LOW 30
- TI-2021-14392 Link following in RPMPriority LOW 28
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2022:0368 |
| Red Hat Enterprise Linux AppStream EUS (v. 8.2) | Fixed | RHSA-2022:0634 |
| Red Hat Enterprise Linux AppStream EUS (v.8.4) | Fixed | RHSA-2022:0254 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2022:0368 |
| Red Hat Enterprise Linux BaseOS EUS (v. 8.2) | Fixed | RHSA-2022:0634 |
| Red Hat Enterprise Linux BaseOS EUS (v.8.4) | Fixed | RHSA-2022:0254 |
Not affected: 1 product
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-3521
- 2026-10-03 Alias added: GHSA-pr6x-p264-jrpq
References
More Rpm vulnerabilities
- TI-2014-06733 Integer overflow in RPM 4.12 and earlier allows remote attackers to execute arbitrary… CVSS 2.0HIGH 10.0
- TI-2011-02988 RPM 4.4.x through 4.9.x, probably before 4.9.1.2, allows remote attackers to cause a… CVSS 2.0HIGH 9.3
- TI-2013-05388 Race condition in RPM 4.11.1 and earlier allows remote attackers to execute arbitrary… CVSS 2.0HIGH 7.6
- TI-2012-00752 The headerVerifyInfo function in lib/header.c in RPM before 4.9.1.3 allows remote… CVSS 2.0MEDIUM 6.8
- TI-2012-00060 The headerLoad function in lib/header.c in RPM before 4.9.1.3 does not properly validate… CVSS 2.0MEDIUM 6.8
- TI-2012-00059 RPM before 4.9.1.3 does not properly validate region tags, which allows remote attackers… CVSS 2.0MEDIUM 6.8
Sources
- CVE-2021-3521 · CVE Program
- CVE-2021-3521 · NVD
- FIRST EPSS
- GHSA-pr6x-p264-jrpq · GitHub Advisory Database · CC BY 4.0
- CVE-2021-3521 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences