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.

New upstream release. This is a security release with a fix for CVE-2017-12425, a crash bug that might be used in a denial of service attack. Details from the upstream project are found here :

http://varnish-cache.org/security/VSV00001.html

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

A denial of service vulnerability was discovered in Varnish, a state of the art, high-performance web accelerator. Specially crafted HTTP requests can cause the Varnish daemon to assert and restart, clearing the cache in the process.

See https://varnish-cache.org/security/VSV00001.html for details.

ID	Name	Product	Family	Severity
102489	Fedora 25 : varnish (2017-bfbc5de1b1)	Nessus	Fedora Local Security Checks	high
102485	Fedora 26 : varnish (2017-8f4fba5afa)	Nessus	Fedora Local Security Checks	high
102135	Debian DSA-3924-1 : varnish - security update	Nessus	Debian Local Security Checks	high

Detections

Analytics

CVE-2017-12425

high

Tenable Plugins

high

high

high