CVE-2021-25321Public exploit

Root privilege escalation via symlink-following chown

Published Jun 30, 2021 · Updated Sep 16, 2024

Symlink following in affected SUSE arpwatch packages allows local users controlling the runtime account to gain root after a restart. The SUSE downstream dropprivileges function calls chown on /var/lib/arpwatch and its arp.dat path without preventing symbolic-link traversal, so a crafted arp.dat link transfers ownership of an attacker-chosen root file. The attacker must first control the unprivileged arpwatch runtime account and then wait for or force a service restart; the ownership change permits modification of the target file and subsequent root access.

CVSS severity7.7
High
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Symlink following in affected SUSE arpwatch packages allows local users controlling the runtime account to gain root after a restart. The SUSE downstream dropprivileges function calls chown on /var/lib/arpwatch and its arp.dat path without preventing symbolic-link traversal, so a crafted arp.dat link transfers ownership of an attacker-chosen root file. The attacker must first control the unprivileged arpwatch runtime account and then wait for or force a service restart; the ownership change permits modification of the target file and subsequent root access.

The record

CVE
CVE-2021-25321
Published
Jun 30, 2021
Updated
Sep 16, 2024
Vendor
OpenSUSE
Product
openSUSE Leap
Classifications
CWE-61, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 30, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=arpwatch <=2.1a15-lp152.5.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

OpenSUSE · openSUSE Leapversion=arpwatch <=2.1a15-lp152.5.5
NeuVector · SUSE OpenStack Cloud Crowbarversion=arpwatch <2.1a15
NeuVector · SUSE Manager Serverversion=arpwatch <2.1a15
NeuVector · SUSE Linux Enterprise Serverversion=arpwatch <2.1a15
OpenSUSE · openSUSE Factoryversion=arpwatch <=2.1a15-169.5

Published CVSS scores

7.2NVDAV:L/AC:L/Au:N/C:C/I:C/A:C
7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.7SUSECVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitPublished

Weakness, pattern, technique

CWE-61UNIX Symbolic Link (Symlink) Following
T1068Exploitation for Privilege Escalation

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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