CVE-2019-12522

Root privilege escalation via retained saved UID

Published Apr 15, 2020 · Updated Aug 4, 2024

Improper privilege management in Squid through 4.7 allows local users to regain root privileges via a compromised child process. The leave_suid call drops the child process to a lesser user while retaining a saved UID of 0, permitting restoration of effective root privileges. Exploitation requires prior compromise of the child process and Squid running as root; the resulting impact is root-level confidentiality, integrity, and availability compromise.

CVSS severity4.5
Medium
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper privilege management in Squid through 4.7 allows local users to regain root privileges via a compromised child process. The leave_suid call drops the child process to a lesser user while retaining a saved UID of 0, permitting restoration of effective root privileges. Exploitation requires prior compromise of the child process and Squid running as root; the resulting impact is root-level confidentiality, integrity, and availability compromise.

The record

CVE
CVE-2019-12522
Published
Apr 15, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-269, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 15, 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

4.5NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
4.4NIST NVDAV:L/AC:M/Au:N/C:P/I:P/A:P

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-269Improper Privilege Management
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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