CVE-2021-3421Public exploit

Database corruption via unchecked signature-header tag copying

Published May 19, 2021 · Updated Aug 3, 2024

Improper signature verification in RPM before 4.17.0-alpha allows attackers to corrupt the RPM database via a crafted package. rpmReadPackageFile calls headerMergeLegacySigs, which copied unexpected or ill-typed entries from the unverified signature header into package metadata without restricting tags or validating type and count. Installation by a local user, or delivery through a compromised repository, is required; the demonstrated consequence is database corruption.

CVSS severity5.5
Medium
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper signature verification in RPM before 4.17.0-alpha allows attackers to corrupt the RPM database via a crafted package. rpmReadPackageFile calls headerMergeLegacySigs, which copied unexpected or ill-typed entries from the unverified signature header into package metadata without restricting tags or validating type and count. Installation by a local user, or delivery through a compromised repository, is required; the demonstrated consequence is database corruption.

The record

CVE
CVE-2021-3421
Published
May 19, 2021
Updated
Aug 3, 2024
Vendor
RPM Software Management
Product
RPM Package Manager
Classifications
CWE-347, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 19, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=rpm 4.17.0-alpha

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

RPM Software Management · RPM Package Managerversion=rpm 4.17.0-alpha

Published CVSS scores

5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
4.3NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
5.5NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
5.3SUSECVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
4.7Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature
T1204.002User Execution: Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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