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Fencer Intel
critical 9.8

CVE-2011-4973 json

Authentication bypass vulnerability in mod_nss 1.0.8 allows remote attackers to assume the identity of a valid user by using their certific…

published 2018-02-15 8 y ago modified 2026-06-16 4 mo ago also EUVD-2011-4878

cvss
9.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 63%
public exploits
0
none known

Summary

Authentication bypass vulnerability in mod_nss 1.0.8 allows remote attackers to assume the identity of a valid user by using their certificate and entering 'password' as the password.

Patch / fix

  • mod_nss RHEL 5 1.0.8-7.el5
  • mod_nss RHEL 6 1.0.8-13.el6

red hat advisories RHBA-2013:0009RHBA-2011:1656

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-2011-4973 updated cvss 4.0

mod_nss: FakeBasicAuth authentication bypass

  • Red Hat Certificate System 8 mod_nss Red Hat Directory Server 8 fortitude-mod_nss
    affected: no fix available
  • Red Hat Enterprise Linux (v. 5 server) mod_nss 1.0.8-7.el5 Red Hat Enterprise Linux Desktop (v. 5 client) mod_nss 1.0.8-7.el5
    fixed: vendor fix RHBA-2013:0009
  • Red Hat Enterprise Linux Desktop Optional (v. 6) mod_nss 1.0.8-13.el6 Red Hat Enterprise Linux HPC Node Optional (v. 6) mod_nss 1.0.8-13.el6 Red Hat Enterprise Linux Server (v. 6) mod_nss 1.0.8-13.el6 Red Hat Enterprise Linux Workstation (v. 6) mod_nss 1.0.8-13.el6
    fixed: vendor fix RHBA-2011:1656
  • Red Hat Enterprise Linux 7 mod_nss
    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

1.00% chance of exploitation in the next 30 days, higher than 63% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness

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.