DNS: DNSmasq multiple Out-of-Bounds Write

This signature detects attempts to exploit a known vulnerability against DNSmasq. A successful attack can lead to a buffer overflow and arbitrary remote code execution within the context of the DNSmasq service.

Extended 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.

Affected Products

Debian debian_linux

References

CVE: CVE-2020-25682

URL: https://www.jsof-tech.com/disclosures/dnspooq/ http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2021q1/014599.html

Short Name

DNS:OVERFLOW:DNSMASQ-MUL-OOB

Severity

Major

Recommended

False

Recommended Action

Drop

DNS: DNSmasq multiple Out-of-Bounds Write

Extended Description

Affected Products

References

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