CVE-2021-35938

Local privilege escalation via symlink metadata race

Published Aug 25, 2022 · Updated Aug 4, 2024

Improper link resolution in RPM Package Manager before 4.18.0 allows local users to gain elevated privileges during package installation. In lib/fsm.c, rpmPackageFilesInstall applies ownership, mode, and capabilities after file creation through a path that can be replaced with a symlink before metadata is set. Exploitation requires control of a writable installation path while a privileged RPM transaction runs and can redirect metadata changes to a security-critical file.

CVSS severity6.7
Medium
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper link resolution in RPM Package Manager before 4.18.0 allows local users to gain elevated privileges during package installation. In lib/fsm.c, rpmPackageFilesInstall applies ownership, mode, and capabilities after file creation through a path that can be replaced with a symlink before metadata is set. Exploitation requires control of a writable installation path while a privileged RPM transaction runs and can redirect metadata changes to a security-critical file.

The record

CVE
CVE-2021-35938
Published
Aug 25, 2022
Updated
Aug 4, 2024
Vendor
RPM Software Management
Product
RPM Package Manager
Classifications
CWE-59, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 25, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=Fixed in rpm v4.18.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

RPM Software Management · RPM Package Managerversion=Fixed in rpm v4.18.0

Published CVSS scores

6.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H
6.7NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-59Improper Link Resolution Before File Access ('Link Following')
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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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