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Fencer Vulns
medium 4.9

CVE-2009-2847 json

The do_sigaltstack function in kernel/signal.c in Linux kernel 2.4 through 2.4.37 and 2.6 before 2.6.31-rc5, when running on 64-bit systems…

published 2009-08-18 17 y ago modified 2026-06-16 4 mo ago also EUVD-2009-2837

cvss
4.9
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 61%
public exploits
1
Exploit-DB

Summary

The do_sigaltstack function in kernel/signal.c in Linux kernel 2.4 through 2.4.37 and 2.6 before 2.6.31-rc5, when running on 64-bit systems, does not clear certain padding bytes from a structure, which allows local users to obtain sensitive information from the kernel stack via the sigaltstack function.

Patch / fix

  • kernel RHEL 4 2.6.9-89.0.11.EL
  • kernel-smp RHEL 4 2.6.9-89.0.11.EL
  • kernel-xenU RHEL 4 2.6.9-89.0.11.EL
  • kernel-hugemem RHEL 4 2.6.9-89.0.11.EL
  • kernel-largesmp RHEL 4 2.6.9-89.0.11.EL
  • kernel RHEL 5 2.6.18-164.el5
  • kernel-PAE RHEL 5 2.6.18-164.el5
  • kernel-xen RHEL 5 2.6.18-164.el5

red hat advisories RHSA-2009:1438RHSA-2009:1243RHSA-2009:1466RHSA-2009:1239

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-2009-2847 updated cvss 2.1

kernel: information leak in sigaltstack

  • Red Hat MRG Realtime for RHEL 5 Server kernel-rt 2.6.24.7-132.el5rt, kernel-rt-trace 2.6.24.7-132.el5rt, kernel-rt-vanilla 2.6.24.7-132.el5rt, kernel-rt-debuginfo-common 2.6.24.7-132.el5rt
    fixed: vendor fix RHSA-2009:1239
  • Red Hat Enterprise Linux (v. 5 server) kernel 2.6.18-164.el5, kernel-PAE 2.6.18-164.el5, kernel-xen 2.6.18-164.el5, kernel-kdump 2.6.18-164.el5, kernel-debuginfo-common 2.6.18-164.el5
    fixed: vendor fix RHSA-2009:1243
  • Red Hat Enterprise Linux AS version 4 kernel 2.6.9-89.0.11.EL, kernel-smp 2.6.9-89.0.11.EL, kernel-xenU 2.6.9-89.0.11.EL, kernel-hugemem 2.6.9-89.0.11.EL, kernel-largesmp 2.6.9-89.0.11.EL
    fixed: vendor fix RHSA-2009:1438
  • Red Hat Enterprise Linux Desktop (v. 5 client) kernel 2.6.18-164.el5, kernel-PAE 2.6.18-164.el5, kernel-xen 2.6.18-164.el5, kernel-kdump 2.6.18-164.el5, kernel-debuginfo-common 2.6.18-164.el5
    fixed: vendor fix RHSA-2009:1243
  • Red Hat Enterprise Linux Desktop version 4 kernel 2.6.9-89.0.11.EL, kernel-smp 2.6.9-89.0.11.EL, kernel-xenU 2.6.9-89.0.11.EL, kernel-hugemem 2.6.9-89.0.11.EL, kernel-largesmp 2.6.9-89.0.11.EL Red Hat Enterprise Linux ES version 4 kernel 2.6.9-89.0.11.EL, kernel-smp 2.6.9-89.0.11.EL, kernel-xenU 2.6.9-89.0.11.EL, kernel-hugemem 2.6.9-89.0.11.EL, kernel-largesmp 2.6.9-89.0.11.EL
    fixed: vendor fix RHSA-2009:1438
  • Red Hat Enterprise Linux EUS (v. 5.3 server) kernel 2.6.18-128.8.1.el5, kernel-PAE 2.6.18-128.8.1.el5, kernel-xen 2.6.18-128.8.1.el5, kernel-kdump 2.6.18-128.8.1.el5, kernel-debuginfo-common 2.6.18-128.8.1.el5
    fixed: vendor fix RHSA-2009:1466
  • Red Hat Enterprise Linux WS version 4 kernel 2.6.9-89.0.11.EL, kernel-smp 2.6.9-89.0.11.EL, kernel-xenU 2.6.9-89.0.11.EL, kernel-hugemem 2.6.9-89.0.11.EL, kernel-largesmp 2.6.9-89.0.11.EL
    fixed: vendor fix RHSA-2009:1438

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

Timeline

  1. First public exploit (EDB-9352)
  2. Published

Exploit prediction

0.94% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • EDB-9352 Linux Kernel 2.6.31-rc5 - sigaltstack 4-Byte Stack Disclosure local, 2009-08-04

CVSS scores

assigned by version score vector
NVD 2.0 4.9 AV:L/AC:L/Au:N/C:C/I:N/A:N

Classification

Technology feeds

References

Sources

Fencer Vulns 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.