An integer overflow flaw, leading to assertion failure, was found in the way Varnish handled chunk sizes in HTTP requests. A remote attacker could use this flaw to make the Varnish daemon restart unexpectedly due to an assertion failure by sending a specially crafted HTTP request.
Missing check for integer overflow was found in the code handling chunk sizes in HTTP requests. The vulnerability opens up for denial of service (DOS) attacks by a specially crafted HTTP request, which will cause the Varnish daemon to assert and restart, clearing the cache in the process. There is no risk for information leakage or remote execution. The vulnerability is present in all releases of Varnish Cache since version 4.0.1.
Name: the Varnish Cache project
Created attachment 1307655 [details]
varnish 4.0 patch
Created attachment 1307656 [details]
varnish 4.1 patch
Created attachment 1307657 [details]
varnish 5.0 patch
Created attachment 1307658 [details]
varnish 5.1 patch
Created varnish tracking bugs for this issue:
Affects: epel-all [bug 1477699]
Affects: fedora-all [bug 1477698]