CVE-2020-25683 Memory corruption in dnsmasq
Remote attackers can cause a denial of service in dnsmasq via heap overflow when DNSSEC is enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-25683?
CVE-2020-25683 is a medium-severity memory corruption vulnerability in Debian Debian Linux, published on 20 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-122
Which versions are affected by CVE-2020-25683?
It affects 3 products.
Products include Debian Debian Linux, Fedoraproject Fedora, Thekelleys Dnsmasq.
How do I fix CVE-2020-25683?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2020-25683 being exploited?
There is no known exploitation of CVE-2020-25683 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as ALPINE-CVE-2020-25683, CLEANSTART-2026-RB80437, DEBIAN-CVE-2020-25683, GHSA-4g83-8xc3-pp6v, UBUNTU-CVE-2020-25683.