CVE-2020-25687

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. This flaw allows a remote attacker, who can create valid DNS replies, 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 sort_rrset() and cause a crash in dnsmasq, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

References

https://bugzilla.redhat.com/show_bug.cgi?id=1891568

https://lists.debian.org/debian-lts-announce/2021/03/msg00027.html

https://lists.fedoraproject.org/archives/list/[email protected]/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/

https://lists.fedoraproject.org/archives/list/[email protected]/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/

https://security.gentoo.org/glsa/202101-17

https://www.debian.org/security/2021/dsa-4844

https://www.jsof-tech.com/disclosures/dnspooq/

Details

Risk Information

CVSS v2

CVSS v3