CVE-2020-25687 (GCVE-0-2020-25687)
Vulnerability from cvelistv5 – Published: 2021-01-20 16:31 – Updated: 2025-11-04 19:12
VLAI
EPSS
VEX
Summary
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.
Severity
5.9 (Medium)
CWE
Assigner
References
8 references
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|---|---|
| https://www.jsof-tech.com/disclosures/dnspooq/ | x_refsource_MISC |
| https://bugzilla.redhat.com/show_bug.cgi?id=1891568 | x_refsource_MISC |
| https://lists.fedoraproject.org/archives/list/pac… | vendor-advisoryx_refsource_FEDORA |
| https://security.gentoo.org/glsa/202101-17 | vendor-advisoryx_refsource_GENTOO |
| https://www.debian.org/security/2021/dsa-4844 | vendor-advisoryx_refsource_DEBIAN |
| https://lists.fedoraproject.org/archives/list/pac… | vendor-advisoryx_refsource_FEDORA |
| https://lists.debian.org/debian-lts-announce/2021… | mailing-listx_refsource_MLIST |
| https://www.kb.cert.org/vuls/id/434904 |
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