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Fencer Vulns
high 7.2

CVE-2009-1895 json

The personality subsystem in the Linux kernel before 2.6.31-rc3 has a PER_CLEAR_ON_SETID setting that does not clear the ADDR_COMPAT_LAYOUT…

published 2009-07-16 17 y ago modified 2026-06-16 4 mo ago also EUVD-2009-1890

cvss
7.2
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

The personality subsystem in the Linux kernel before 2.6.31-rc3 has a PER_CLEAR_ON_SETID setting that does not clear the ADDR_COMPAT_LAYOUT and MMAP_PAGE_ZERO flags when executing a setuid or setgid program, which makes it easier for local users to leverage the details of memory usage to (1) conduct NULL pointer dereference attacks, (2) bypass the mmap_min_addr protection mechanism, or (3) defeat address space layout randomization (ASLR).

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 5.3 EUS, RHEL 5 2.6.18-128.4.1.el5
  • kernel-PAE RHEL 5.3 EUS, RHEL 5 2.6.18-128.4.1.el5
  • kernel-xen RHEL 5.3 EUS, RHEL 5 2.6.18-128.4.1.el5

red hat advisories RHSA-2009:1438RHSA-2009:1193RHSA-2010:0079RHSA-2009:1550RHSA-2009:1540

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-2009-1895 updated cvss 2.1

kernel: personality: fix PER_CLEAR_ON_SETID

  • Red Hat MRG Realtime for RHEL 5 Server kernel-rt 2.6.24.7-137.el5rt, kernel-rt-trace 2.6.24.7-137.el5rt, kernel-rt-vanilla 2.6.24.7-137.el5rt, kernel-rt-debuginfo-common 2.6.24.7-137.el5rt
    fixed: vendor fix RHSA-2009:1540
  • Red Hat Desktop version 3 kernel 2.4.21-63.EL, kernel-smp 2.4.21-63.EL, kernel-BOOT 2.4.21-63.EL, kernel-source 2.4.21-63.EL, kernel-hugemem 2.4.21-63.EL, kernel-unsupported 2.4.21-63.EL, +2 more
    fixed: vendor fix RHSA-2009:1550
  • Red Hat Enterprise Linux (v. 5 server) kernel 2.6.18-128.4.1.el5, kernel-PAE 2.6.18-128.4.1.el5, kernel-xen 2.6.18-128.4.1.el5, kernel-kdump 2.6.18-128.4.1.el5, kernel-debuginfo-common 2.6.18-128.4.1.el5
    fixed: vendor fix RHSA-2009:1193
  • Red Hat Enterprise Linux AS version 3 kernel 2.4.21-63.EL, kernel-smp 2.4.21-63.EL, kernel-BOOT 2.4.21-63.EL, kernel-source 2.4.21-63.EL, kernel-hugemem 2.4.21-63.EL, kernel-unsupported 2.4.21-63.EL, +2 more
    fixed: vendor fix RHSA-2009:1550
  • 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 2.6.18-128.4.1.el5, kernel-PAE 2.6.18-128.4.1.el5, kernel-xen 2.6.18-128.4.1.el5, kernel-kdump 2.6.18-128.4.1.el5, kernel-debuginfo-common 2.6.18-128.4.1.el5
    fixed: vendor fix RHSA-2009:1193
  • 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
    fixed: vendor fix RHSA-2009:1438
  • Red Hat Enterprise Linux ES version 3 kernel 2.4.21-63.EL, kernel-smp 2.4.21-63.EL, kernel-BOOT 2.4.21-63.EL, kernel-source 2.4.21-63.EL, kernel-hugemem 2.4.21-63.EL, kernel-unsupported 2.4.21-63.EL, +2 more
    fixed: vendor fix RHSA-2009:1550
show 5 more
  • 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. 5.2 server) kernel 2.6.18-92.1.35.el5, kernel-PAE 2.6.18-92.1.35.el5, kernel-xen 2.6.18-92.1.35.el5, kernel-kdump 2.6.18-92.1.35.el5, kernel-debuginfo-common 2.6.18-92.1.35.el5
    fixed: vendor fix RHSA-2010:0079
  • Red Hat Enterprise Linux EUS (v. 5.3 server) kernel 2.6.18-128.4.1.el5, kernel-PAE 2.6.18-128.4.1.el5, kernel-xen 2.6.18-128.4.1.el5, kernel-kdump 2.6.18-128.4.1.el5, kernel-debuginfo-common 2.6.18-128.4.1.el5
    fixed: vendor fix RHSA-2009:1193
  • Red Hat Enterprise Linux WS version 3 kernel 2.4.21-63.EL, kernel-smp 2.4.21-63.EL, kernel-BOOT 2.4.21-63.EL, kernel-source 2.4.21-63.EL, kernel-hugemem 2.4.21-63.EL, kernel-unsupported 2.4.21-63.EL, +2 more
    fixed: vendor fix RHSA-2009:1550
  • 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

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 2.0 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness
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.