The ClamAV AntiVirus software versions 0.99.2 and prior contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to a lack of input validation checking mechanisms during certain mail parsing operations (mbox.c operations on bounce messages). If successfully exploited, the ClamAV software could allow a variable pointing to the mail body which could cause a used after being free (use-after-free) instance which may lead to a disruption of services on an affected device to include a denial of service condition.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
| Link | Tags |
|---|---|
| https://usn.ubuntu.com/3550-1/ | vendor advisory |
| https://usn.ubuntu.com/3550-2/ | vendor advisory |
| https://lists.debian.org/debian-lts-announce/2018/01/msg00035.html | third party advisory mailing list |
| http://blog.clamav.net/2018/01/clamav-0993-has-been-released.html | release notes vendor advisory |
| https://bugzilla.clamav.net/show_bug.cgi?id=11939 | issue tracking patch vendor advisory exploit |