How severe is CVE-2019-12522?

CVE-2019-12522 has a CVSS 3.x base score of 4.5, rated medium severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2019-12522 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-12522?

CVE-2019-12522 affects Squid-cache Squid. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-12522?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2019-12522 published?

CVE-2019-12522 was published on 2020-04-15 and last updated on 2026-06-17.

CVE-2019-12522

CVE-2019-12522 is a medium-severity vulnerability in Squid-cache Squid with a CVSS 3.x base score of 4.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-269.

Key facts

Severity: Medium (CVSS 3.x base score 4.5)
CVSS v2: 4.4
EPSS exploit prediction: 0% (26th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-269
Affected product: Squid-cache Squid
Published: 2020-04-15
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2019-12522?: 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.
How severe is CVE-2019-12522?: CVE-2019-12522 has a CVSS 3.x base score of 4.5, rated medium severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2019-12522 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-12522?: CVE-2019-12522 affects Squid-cache Squid. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-12522?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2019-12522 published?: CVE-2019-12522 was published on 2020-04-15 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

200.89.159.59 (ipv4-addr)
192.3.127.40 (ipv4-addr)