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Fencer Intel
medium 4.7

CVE-2012-4565 json

The tcp_illinois_info function in net/ipv4/tcp_illinois.c in the Linux kernel before 3.4.19, when the net.ipv4.tcp_congestion_control illin…

published 2012-12-21 13 y ago modified 2026-06-16 4 mo ago also EUVD-2012-4493

cvss
4.7
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 42%
public exploits
0
none known

Summary

The tcp_illinois_info function in net/ipv4/tcp_illinois.c in the Linux kernel before 3.4.19, when the net.ipv4.tcp_congestion_control illinois setting is enabled, allows local users to cause a denial of service (divide-by-zero error and OOPS) by reading TCP stats.

Patch / fix

  • linux Debian 14, Debian 13, Debian 12 3.2.35-1

debian advisories DEBIAN-CVE-2012-4565

  • kernel RHEL 6 2.6.32-279.19.1.el6
  • perf RHEL 6 2.6.32-279.19.1.el6
  • python-perf RHEL 6 2.6.32-279.19.1.el6
  • kernel-kdump RHEL 6 2.6.32-279.19.1.el6
  • kernel-firmware RHEL 6 2.6.32-279.19.1.el6
  • kernel-bootwrapper RHEL 6 2.6.32-279.19.1.el6
  • kernel-debuginfo-common-i686 RHEL 6 2.6.32-279.19.1.el6
  • kernel-debuginfo-common-ppc64 RHEL 6 2.6.32-279.19.1.el6

red hat advisories RHSA-2012:1580RHSA-2012:1491

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-2012-4565 updated cvss 4.7

kernel: net: divide by zero in tcp algorithm illinois

  • Red Hat Enterprise Linux Desktop (v. 6) perf 2.6.32-279.19.1.el6, kernel 2.6.32-279.19.1.el6, kernel-firmware 2.6.32-279.19.1.el6, kernel-debuginfo-common-i686 2.6.32-279.19.1.el6, kernel-debuginfo-common-x86_64 2.6.32-279.19.1.el6 Red Hat Enterprise Linux Desktop Optional (v. 6) kernel 2.6.32-279.19.1.el6, python-perf 2.6.32-279.19.1.el6, kernel-debuginfo-common-i686 2.6.32-279.19.1.el6, kernel-debuginfo-common-x86_64 2.6.32-279.19.1.el6 Red Hat Enterprise Linux HPC Node (v. 6) perf 2.6.32-279.19.1.el6, kernel 2.6.32-279.19.1.el6, kernel-firmware 2.6.32-279.19.1.el6, kernel-debuginfo-common-x86_64 2.6.32-279.19.1.el6 Red Hat Enterprise Linux HPC Node Optional (v. 6) kernel 2.6.32-279.19.1.el6, python-perf 2.6.32-279.19.1.el6, kernel-debuginfo-common-x86_64 2.6.32-279.19.1.el6 Red Hat Enterprise Linux Server (v. 6) perf 2.6.32-279.19.1.el6, kernel 2.6.32-279.19.1.el6, kernel-kdump 2.6.32-279.19.1.el6, kernel-firmware 2.6.32-279.19.1.el6, kernel-bootwrapper 2.6.32-279.19.1.el6, kernel-debuginfo-common-i686 2.6.32-279.19.1.el6, +3 more Red Hat Enterprise Linux Server Optional (v. 6) kernel 2.6.32-279.19.1.el6, python-perf 2.6.32-279.19.1.el6, kernel-debuginfo-common-i686 2.6.32-279.19.1.el6, kernel-debuginfo-common-ppc64 2.6.32-279.19.1.el6, kernel-debuginfo-common-s390x 2.6.32-279.19.1.el6, kernel-debuginfo-common-x86_64 2.6.32-279.19.1.el6
    +2 more products
    Red Hat Enterprise Linux Workstation (v. 6) perf 2.6.32-279.19.1.el6, kernel 2.6.32-279.19.1.el6, kernel-firmware 2.6.32-279.19.1.el6, kernel-debuginfo-common-i686 2.6.32-279.19.1.el6, kernel-debuginfo-common-x86_64 2.6.32-279.19.1.el6 Red Hat Enterprise Linux Workstation Optional (v. 6) kernel 2.6.32-279.19.1.el6, python-perf 2.6.32-279.19.1.el6, kernel-debuginfo-common-i686 2.6.32-279.19.1.el6, kernel-debuginfo-common-x86_64 2.6.32-279.19.1.el6
    fixed: vendor fix RHSA-2012:1580
  • Red Hat MRG Realtime for RHEL 6 Server v.2 kernel-rt 3.2.33-rt50.66.el6rt, mrg-rt-release 3.2.33-rt50.66.el6rt, kernel-rt-trace 3.2.33-rt50.66.el6rt, kernel-rt-vanilla 3.2.33-rt50.66.el6rt, kernel-rt-firmware 3.2.33-rt50.66.el6rt, kernel-rt-debuginfo-common-x86_64 3.2.33-rt50.66.el6rt
    fixed: vendor fix RHSA-2012:1491
  • Red Hat Enterprise Linux 5 kernel
    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

0.49% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/torvalds/linux/commit/8f363b77ee4fbf7c3bbcf5ec2c5ca482d396d664 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 2.0 4.7 AV:L/AC:M/Au:N/C:N/I:N/A:C

Classification

Weakness
Technology feeds

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.