CVE-2020-7040Public exploit

Local privilege escalation via lock-file symlink race

Published Jan 21, 2020 · Updated Aug 4, 2024

Symlink race in storeBackup through 3.5 allows local users to overwrite files or escalate privileges through a fixed lock-file path. storeBackup.pl calls stat() and then lstat() on /tmp/storeBackup.lock before opening the pathname for creation, leaving a race in which a symlink redirects a root-run write. The program typically runs as root; a plain file at the same path also makes backup jobs exit immediately, causing a local service interruption.

CVSS severity8.1
High
EPSS probability2.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Symlink race in storeBackup through 3.5 allows local users to overwrite files or escalate privileges through a fixed lock-file path. storeBackup.pl calls stat() and then lstat() on /tmp/storeBackup.lock before opening the pathname for creation, leaving a race in which a symlink redirects a root-run write. The program typically runs as root; a plain file at the same path also makes backup jobs exit immediately, causing a local service interruption.

The record

CVE
CVE-2020-7040
Published
Jan 21, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-59, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 21, 2020CVE 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.1NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/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 exploitPublished

Weakness, pattern, technique

CWE-59Improper Link Resolution Before File Access ('Link 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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