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Fencer Intel
medium 5.0

CVE-2011-4096 json

The idnsGrokReply function in Squid before 3.1.16 does not properly free memory, which allows remote attackers to cause a denial of service…

published 2011-11-17 14 y ago modified 2026-06-16 4 mo ago also EUVD-2011-4047

cvss
5.0
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
37.2%
EPSS 37.2% chance of exploitation in 30 days, percentile 98%
public exploits
0
none known

Summary

The idnsGrokReply function in Squid before 3.1.16 does not properly free memory, which allows remote attackers to cause a denial of service (daemon abort) via a DNS reply containing a CNAME record that references another CNAME record that contains an empty A record.

Patch / fix

  • squid RHEL 6 7:3.1.10-1.el6_2.1

red hat advisories RHSA-2011:1791

  • squid3 SLES for SAP 11 SP4, SLES 11 SP4 3.1.23-8.16.30.1

suse advisories SUSE-SU-2016:2089-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2011-4096 updated cvss 3.3

squid: Invalid free by processing CNAME DNS record pointing to another CNAME record pointing to an empty A-record

  • Red Hat Enterprise Linux Server (v. 6) squid 3.1.10-1.el6_2.1 Red Hat Enterprise Linux Workstation (v. 6) squid 3.1.10-1.el6_2.1
    fixed: vendor fix RHSA-2011:1791
  • Red Hat Enterprise Linux 4 squid Red Hat Enterprise Linux 5 squid
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

37.19% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness
  • CWE-399 Resource Management Errors

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.