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Fencer Vulns
critical 9.1

CVE-2006-4339 in the critical feed json

Openssl: openssl: signature forgery via improper pkcs-1 padding removal leading to certificate validation bypass

published 2006-09-05 20 y ago modified 2026-11-04 4 d ago also EUVD-2006-4327

cvss
9.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
3.9%
EPSS 3.9% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

A flaw was found in OpenSSL. When configured to use an RSA key with exponent 3, OpenSSL improperly removes PKCS-1 padding before generating a hash. This allows remote attackers to forge PKCS #1 v1.5 signatures. Consequently, OpenSSL may incorrectly verify X.509 and other certificates, leading to a bypass of trust and authentication mechanisms.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 3 0:0.9.6b-16.43, 0:0.9.7a-33.18
  • Red Hat Red Hat Enterprise Linux 4 0:0.9.6b-22.43, 0:0.9.7a-43.11
  • Red Hat Red Hat Network Satellite Server v 4.2 0:1-0, 0:5.0.2-3
  • Red Hat Red Hat Network Satellite Server v 4.2 (RHEL3) 0:1-0, 0:5.0.2-3
  • Red Hat Red Hat Network Satellite Server v 5.0 0:1-0, 0:5.0.2-3
  • Red Hat Red Hat Network Satellite Server v 5.1 0:1-0, 0:5.1.1-3
  • openssl Debian 14, Debian 13, Debian 12 0.9.8b-3

debian advisories DEBIAN-CVE-2006-4339

  • rhn-solaris-bootstrap network satellite 5.1 5.1.1-3
  • rhn_solaris_bootstrap_5_1_1_3 network satellite 5.1 1-0
  • rhn-solaris-bootstrap network satellite 5.0, network satellite 4.2 5.0.2-3
  • rhn_solaris_bootstrap_5_0_2_3 network satellite 5.0, network satellite 4.2 1-0

red hat advisories RHSA-2008:0629RHSA-2008:0525RHSA-2008:0264

  • bind openSUSE Tumbleweed 9.16.20-1.4
  • openssl-1_0_0 openSUSE Tumbleweed 1.0.2u-6.2
  • openssl-1_1 openSUSE Tumbleweed 1.1.1l-1.2
  • openvpn openSUSE Tumbleweed 2.5.3-1.2

opensuse advisories openSUSE-SU-2024:10650-1openSUSE-SU-2024:11126-1openSUSE-SU-2024:11127-1openSUSE-SU-2024:11128-1

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-2006-4339 updated cvss 9.1

OpenSSL: OpenSSL: Signature forgery via improper PKCS-1 padding removal leading to certificate validation bypass

  • Red Hat Desktop version 3 openssl 0.9.7a-33.18, openssl096b 0.9.6b-16.43, openssl-perl 0.9.7a-33.18 Red Hat Enterprise Linux AS version 3 openssl 0.9.7a-33.18, openssl096b 0.9.6b-16.43, openssl-perl 0.9.7a-33.18 Red Hat Enterprise Linux AS version 4 openssl 0.9.7a-43.11, openssl096b 0.9.6b-22.43, openssl-perl 0.9.7a-43.11 Red Hat Enterprise Linux Desktop version 4 openssl 0.9.7a-43.11, openssl096b 0.9.6b-22.43, openssl-perl 0.9.7a-43.11 Red Hat Enterprise Linux ES version 3 openssl 0.9.7a-33.18, openssl096b 0.9.6b-16.43, openssl-perl 0.9.7a-33.18 Red Hat Enterprise Linux ES version 4 openssl 0.9.7a-43.11, openssl096b 0.9.6b-22.43, openssl-perl 0.9.7a-43.11
    +2 more products
    Red Hat Enterprise Linux WS version 3 openssl 0.9.7a-33.18, openssl096b 0.9.6b-16.43, openssl-perl 0.9.7a-33.18 Red Hat Enterprise Linux WS version 4 openssl 0.9.7a-43.11, openssl096b 0.9.6b-22.43, openssl-perl 0.9.7a-43.11
    fixed: vendor fix RHSA-2006:0661
  • Red Hat Satellite 5.0 (RHEL v.4 AS) rhn-solaris-bootstrap 5.0.2-3, rhn_solaris_bootstrap_5_0_2_3 1-0
    fixed: vendor fix RHSA-2008:0264
  • Red Hat Satellite 5.1 (RHEL v.4 AS) rhn-solaris-bootstrap 5.1.1-3, rhn_solaris_bootstrap_5_1_1_3 1-0
    fixed: vendor fix RHSA-2008:0629
  • Red Hat Satellite v 4.2 (RHEL v.3 AS) rhn-solaris-bootstrap 5.0.2-3, rhn_solaris_bootstrap_5_0_2_3 1-0 Red Hat Satellite v 4.2 (RHEL v.4 AS) rhn-solaris-bootstrap 5.0.2-3, rhn_solaris_bootstrap_5_0_2_3 1-0
    fixed: vendor fix RHSA-2008:0525
  • Red Hat Enterprise Linux 6 openssl, openssl-perl Red Hat Enterprise Linux 7 ovmf, OVMF, AAVMF, openssl, openssl-libs, openssl-perl Red Hat Enterprise Linux 8 edk2, shim, openssl, shim-x64, edk2-ovmf, shim-aa64, +9 more Red Hat Enterprise Linux 9 edk2, shim, openssl, shim-x64, edk2-ovmf, shim-aa64, +7 more Red Hat Enterprise Linux 10 edk2, shim, openssl, shim-unsigned-x64, shim-unsigned-aarch64 Red Hat JBoss Core Services openssl
    +1 more products
    Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    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

3.95% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N

Affected products

  • Red Hat Red Hat Enterprise Linux 3
  • Red Hat Red Hat Enterprise Linux 4
  • Red Hat Red Hat Network Satellite Server v 4.2
  • Red Hat Red Hat Network Satellite Server v 4.2 (RHEL3)
  • Red Hat Red Hat Network Satellite Server v 5.0
  • Red Hat Red Hat Network Satellite Server v 5.1
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat JBoss Core Services
  • Red Hat Red Hat OpenShift Container Platform 4

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature
  • CWE-310 Cryptographic Issues
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.