CVE-2020-25682

A flaw was found in dnsmasq before 2.83. A buffer overflow vulnerability was discovered in the way dnsmasq extract names from DNS packets before validating them with DNSSEC data. An attacker on the network, who can create valid DNS replies, could use this flaw to cause an overflow with arbitrary data in a heap-allocated memory, possibly executing code on the machine. The flaw is in the rfc1035.c:extract_name() function, which writes data to the memory pointed by name assuming MAXDNAME*2 bytes are available in the buffer. However, in some code execution paths, it is possible extract_name() gets passed an offset from the base buffer, thus reducing, in practice, the number of available bytes that can be written in the buffer. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

• CWE-122
• CWE-787

• https://bugzilla.redhat.com/show_bug.cgi?id=1882014Issue Tracking, Patch, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2021/03/msg00027.htmlMailing List, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
• https://security.gentoo.org/glsa/202101-17Third Party Advisory
• https://www.debian.org/security/2021/dsa-4844Third Party Advisory
• https://www.jsof-tech.com/disclosures/dnspooq/Third Party Advisory
• https://bugzilla.redhat.com/show_bug.cgi?id=1882014Issue Tracking, Patch, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2021/03/msg00027.htmlMailing List, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
• https://security.gentoo.org/glsa/202101-17Third Party Advisory
• https://www.debian.org/security/2021/dsa-4844Third Party Advisory
• https://www.jsof-tech.com/disclosures/dnspooq/Third Party Advisory
• https://www.kb.cert.org/vuls/id/434904

Published

Jan 20, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2020-25677A flaw was found in Ceph-ansible v4.0.41 where it creates an…5.5
• CVE-2020-25678A flaw was found in ceph in versions prior to 16.y.z where c…4.4
• CVE-2020-25679Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultID…
• CVE-2020-2568Vulnerability in the Oracle Applications DBA component of Or…3.9
• CVE-2020-25680A flaw was found in JBCS httpd in version 2.4.37 SP3, where …5.4
• CVE-2020-25681A flaw was found in dnsmasq before version 2.83. A heap-base…8.1
• CVE-2020-25683A flaw was found in dnsmasq before version 2.83. A heap-base…5.9
• CVE-2020-25684A flaw was found in dnsmasq before version 2.83. When gettin…3.7
• CVE-2020-25685A flaw was found in dnsmasq before version 2.83. When gettin…3.7
• CVE-2020-25686A flaw was found in dnsmasq before version 2.83. When receiv…3.7
• CVE-2020-25687A flaw was found in dnsmasq before version 2.83. A heap-base…5.9
• CVE-2020-25688A flaw was found in rhacm versions before 2.0.5 and before 2…3.5