CVE-2019-12522 Privilege escalation in n/a
Attackers who compromise a child process can escalate privileges to root if Squid is run as root, due to improper handling of saved UIDs.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2019-12522?
CVE-2019-12522 is a medium-severity vulnerability in Squid-Cache Squid, published on 15 Apr 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An issue was discovered in Squid through 4.7. When Squid is run as root, it spawns its child processes as a lesser user, by default the user nobody. This is done via the leave_suid call. leave_suid leaves the Saved UID as 0. This makes it trivial for an attacker who has compromised the child process to escalate their privileges back to root.
Weakness: CWE-269
Which versions are affected by CVE-2019-12522?
It affects 1 product.
Products include Squid-Cache Squid.
How do I fix CVE-2019-12522?
No fix has been published for CVE-2019-12522 yet. Limit exposure of the affected software until one is available.
Is CVE-2019-12522 being exploited?
There is no known exploitation of CVE-2019-12522 in the wild and no public exploit code.
Other vulnerabilities in Squid-Cache Squid
- CVE-2025-62168 Squid vulnerable to information disclosure via authentication credential leakage in error handling
- CVE-2025-54574 Squid's URN Handling can lead to Buffer Overflow
- CVE-2026-33526 Squid vulnerable to Denial of Service in ICP Request handling
- CVE-2026-32748 Squid has Denial of Service in ICP Response handling
- CVE-2023-50269 SQUID-2023:10 Denial of Service in HTTP Request parsing
Sources
Also known as DEBIAN-CVE-2019-12522, GHSA-rwjf-j42w-jfr4, UBUNTU-CVE-2019-12522.