CVE-2020-25683
Description
A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. A remote attacker, who can create valid DNS replies, could use this flaw to cause an overflow in a heap-allocated memory. This flaw is caused by the lack of length checks in rfc1035.c:extract_name(), which could be abused to make the code execute memcpy() with a negative size in get_rdata() and cause a crash in dnsmasq, resulting in a denial of service. The highest threat from this vulnerability is to system availability.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2020-25683
Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2020-25683.html
Vendor advisory: arch — https://security.archlinux.org/ASA-202101-38
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| arch | fixed | 2.83-1 | |
| sles | affected | | |
| debian | bookworm | fixed | 2.83-1 |
| debian | bullseye | fixed | 2.83-1 |
| debian | forky | fixed | 2.83-1 |
| debian | sid | fixed | 2.83-1 |
| debian | trixie | fixed | 2.83-1 |
References
Verify integrity in audit chain (admin only). AS-IS.