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Fencer Intel
low 2.1

CVE-2011-2495 json

fs/proc/base.c in the Linux kernel before 2.6.39.4 does not properly restrict access to /proc/#####/io files, which allows local users to o…

published 2012-06-13 14 y ago modified 2026-06-16 4 mo ago also EUVD-2011-2482

cvss
2.1
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 41%
public exploits
0
none known

Summary

fs/proc/base.c in the Linux kernel before 2.6.39.4 does not properly restrict access to /proc/#####/io files, which allows local users to obtain sensitive I/O statistics by polling a file, as demonstrated by discovering the length of another user's password.

Patch / fix

  • kernel RHEL 5 2.6.18-274.3.1.el5
  • kernel-PAE RHEL 5 2.6.18-274.3.1.el5
  • kernel-xen RHEL 5 2.6.18-274.3.1.el5
  • kernel-kdump RHEL 5 2.6.18-274.3.1.el5
  • kernel-debuginfo-common RHEL 5 2.6.18-274.3.1.el5
  • kernel RHEL 6 2.6.32-131.12.1.el6
  • perf RHEL 6 2.6.32-131.12.1.el6
  • kernel-kdump RHEL 6 2.6.32-131.12.1.el6

red hat advisories RHSA-2011:1813RHSA-2011:1212RHSA-2011:1189RHSA-2011:1253

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-2011-2495 updated cvss 2.1

kernel: /proc/PID/io infoleak

  • Red Hat Enterprise Linux 4 kernel
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux (v. 5 server) kernel 2.6.18-274.3.1.el5, kernel-PAE 2.6.18-274.3.1.el5, kernel-xen 2.6.18-274.3.1.el5, kernel-kdump 2.6.18-274.3.1.el5, kernel-debuginfo-common 2.6.18-274.3.1.el5 Red Hat Enterprise Linux Desktop (v. 5 client) kernel 2.6.18-274.3.1.el5, kernel-PAE 2.6.18-274.3.1.el5, kernel-xen 2.6.18-274.3.1.el5, kernel-debuginfo-common 2.6.18-274.3.1.el5
    fixed: vendor fix RHSA-2011:1212
  • Red Hat Enterprise Linux EUS (v. 5.6 server) kernel 2.6.18-238.31.1.el5, kernel-PAE 2.6.18-238.31.1.el5, kernel-xen 2.6.18-238.31.1.el5, kernel-kdump 2.6.18-238.31.1.el5, kernel-debuginfo-common 2.6.18-238.31.1.el5
    fixed: vendor fix RHSA-2011:1813
  • Red Hat Enterprise Linux Server (v. 6) perf 2.6.32-131.12.1.el6, kernel 2.6.32-131.12.1.el6, kernel-kdump 2.6.32-131.12.1.el6, kernel-firmware 2.6.32-131.12.1.el6, kernel-bootwrapper 2.6.32-131.12.1.el6, kernel-debuginfo-common-i686 2.6.32-131.12.1.el6, +3 more
    fixed: vendor fix RHSA-2011:1189
  • Red Hat MRG Realtime for RHEL 6 Server v.2 kernel-rt 2.6.33.9-rt31.75.el6rt, kernel-rt-trace 2.6.33.9-rt31.75.el6rt, kernel-rt-vanilla 2.6.33.9-rt31.75.el6rt, kernel-rt-firmware 2.6.33.9-rt31.75.el6rt, kernel-rt-debuginfo-common-x86_64 2.6.33.9-rt31.75.el6rt
    fixed: vendor fix RHSA-2011:1253

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

0.48% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/torvalds/linux/commit/1d1221f375c94ef961ba8574ac4f85c8870ddd51 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 2.0 2.1 AV:L/AC:L/Au:N/C:P/I:N/A:N

Classification

Weakness
  • CWE-264 Permissions, Privileges, and Access Controls
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.