Integer overflow in Varnish-Cache Varnish

CVE-2017-12425

An issue was discovered in Varnish HTTP Cache 4.0.1 through 4.0.4, 4.1.0 through 4.1.7, 5.0.0, and 5.1.0 through 5.1.2. A wrong if statement in the varnishd source code means that particular invalid requests from the client can trigger an assert, related to an Integer Overflow. This causes the varnishd worker process to abort and restart, losing the cached contents in the process. An attacker can therefore crash the varnishd worker process on demand and effectively keep it from serving content - a Denial-of-Service attack. The specific source-code filename containing the incorrect statement varies across releases.

Vulnerability class: Integer Overflow

EPSS: 0.024 (83.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/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-2017-12425?
CVE-2017-12425 is a high-severity vulnerability in Varnish-Cache Varnish, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2017-08-04.
How severe is CVE-2017-12425?
High severity. CVSS v3 base score is 7.5 out of 10.