CVE-2011-1935

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2017-10-20 · updated 2026-06-16

Description

pcap-linux.c in libpcap 1.1.1 before commit ea9432fabdf4b33cbc76d9437200e028f1c47c93 when snaplen is set may truncate packets, which might allow remote attackers to send arbitrary data while avoiding detection via crafted packets.

Affected products

The Tcpdump Group libpcap: from 1.1.1 before 1.2.1 — fixed in 1.2.1

How to fix

Upgrade to a fixed version: The Tcpdump Group libpcap 1.2.1. Check the vendor advisory for mitigations.

References

http://article.gmane.org/gmane.network.tcpdump.devel/4968
http://thread.gmane.org/gmane.network.tcpdump.devel/5018
http://www.openwall.com/lists/oss-security/2011/05/19/11
http://www.openwall.com/lists/oss-security/2014/02/08/5
https://bugs.debian.org/cgi-bin/bugreport.cgi?att=1%3Bbug=623868%3Bfilename=0001-Fix-the-calculation-of-the-frame-size-in-memory-mapp.patch%3Bmsg=10
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=623868
https://security-tracker.debian.org/tracker/CVE-2011-1935/
http://article.gmane.org/gmane.network.tcpdump.devel/4968
http://thread.gmane.org/gmane.network.tcpdump.devel/5018
http://www.openwall.com/lists/oss-security/2011/05/19/11
http://www.openwall.com/lists/oss-security/2014/02/08/5
https://bugs.debian.org/cgi-bin/bugreport.cgi?att=1%3Bbug=623868%3Bfilename=0001-Fix-the-calculation-of-the-frame-size-in-memory-mapp.patch%3Bmsg=10

Get alerted when CVE-2011-1935 or the next vulnerability affects your stack