CVE-2017-13704

Severity: high (CVSS 7.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 65.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2017-10-03 · updated 2026-06-17
Weakness: CWE-20

Description

In dnsmasq before 2.78, if the DNS packet size does not match the expected size, the size parameter in a memset call gets a negative value. As it is an unsigned value, memset ends up writing up to 0xffffffff zero's (0xffffffffffffffff in 64 bit platforms), making dnsmasq crash.

Affected products

Canonical Ubuntu Linux: 14.04, 16.04, 17.04
Debian Linux: 7.0, 7.1, 9.0
Fedoraproject Fedora: 27
Novell Leap: 42.2, 42.3
RedHat Enterprise Linux Desktop: 7.0
RedHat Enterprise Linux Server: 7.0
RedHat Enterprise Linux Workstation: 7.0
Simon Kelley dnsmasq: through 2.77

References

http://thekelleys.org.uk/dnsmasq/CHANGELOG
http://thekelleys.org.uk/gitweb/?p=dnsmasq.git%3Ba=commit%3Bh=63437ffbb58837b214b4b92cb1c54bc5f3279928
http://www.securityfocus.com/bid/101085
http://www.securityfocus.com/bid/101977
http://www.securitytracker.com/id/1039474
https://access.redhat.com/security/vulnerabilities/3199382
https://cert-portal.siemens.com/productcert/pdf/ssa-689071.pdf
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4TK6DWC53WSU6633EVZL7H4PCWBYHMHK/
https://security.googleblog.com/2017/10/behind-masq-yet-more-dns-and-dhcp.html
https://www.mail-archive.com/dnsmasq-discuss%40lists.thekelleys.org.uk/msg11664.html
https://www.mail-archive.com/dnsmasq-discuss%40lists.thekelleys.org.uk/msg11665.html
https://www.synology.com/support/security/Synology_SA_17_59_Dnsmasq

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