Buffer overflow in Squid-Cache Squid

CVE-2019-18676

An issue was discovered in Squid 3.x and 4.x through 4.8. Due to incorrect input validation, there is a heap-based buffer overflow that can result in Denial of Service to all clients using the proxy. Severity is high due to this vulnerability occurring before normal security checks; any remote client that can reach the proxy port can trivially perform the attack via a crafted URI scheme.

Vulnerability class: Buffer Overflow

EPSS: 0.092 (94.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2019-18676?
CVE-2019-18676 is a high-severity vulnerability in Squid-Cache Squid, classified under Out-of-bounds Write. CVSS score: 7.5/10. Published 2019-11-26.
How severe is CVE-2019-18676?
High severity. CVSS v3 base score is 7.5 out of 10.