Description:
According to a vendor security advisory [0], Daniel Bleichenbacher
described a possible attack on PKCS #1 v1.5 signatures which affects
the cryptography and SSL/TLS toolkit OpenSSL [1].
If an RSA key with exponent 3 is used it may be possible to forge
a PKCS #1 v1.5 signature signed by that key. Implementations may
incorrectly verify the certificate if they are not checking for excess
data in the RSA exponentiation result of the signature. Since there
are CAs using exponent 3 in wide use, and PKCS #1 v1.5 is used in
X.509 certificates, all software that uses OpenSSL to verify X.509
certificates is potentially vulnerable, as well as any other use of
PKCS #1 v1.5. This includes software that uses OpenSSL for SSL or TLS.
The Common Vulnerabilities and Exposures (CVE) project assigned the id
CVE-2006-4339 [2] to the problem.
________________________________________________________________________
For security reasons, this advisory was digitally signed with the
OpenPGP public key "OpenPKG <openpkg (at) openpkg (dot) org [email concealed]>" (ID 63C4CB9F) of the
OpenPKG project which you can retrieve from http://pgp.openpkg.org and
hkp://pgp.openpkg.org. Follow the instructions on http://pgp.openpkg.org
for details on how to verify the integrity of this advisory.
________________________________________________________________________
Hash: SHA1
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OpenPKG Security Advisory The OpenPKG Project
http://www.openpkg.org/security/ http://www.openpkg.org
openpkg-security (at) openpkg (dot) org [email concealed] openpkg (at) openpkg (dot) org [email concealed]
OpenPKG-SA-2006.018 06-Sep-2006
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Package: openssl
Vulnerability: signature verification failure
OpenPKG Specific: no
Affected Releases: Affected Packages: Corrected Packages:
OpenPKG CURRENT <= openssl-0.9.8b-20060505 >= openssl-0.9.8c-20060905
OpenPKG 2-STABLE <= openssl-0.9.8b-2.20060622 >= openssl-0.9.8c-2.20060906
OpenPKG 2.5-RELEASE <= openssl-0.9.8a-2.5.1 >= openssl-0.9.8a-2.5.2
Description:
According to a vendor security advisory [0], Daniel Bleichenbacher
described a possible attack on PKCS #1 v1.5 signatures which affects
the cryptography and SSL/TLS toolkit OpenSSL [1].
If an RSA key with exponent 3 is used it may be possible to forge
a PKCS #1 v1.5 signature signed by that key. Implementations may
incorrectly verify the certificate if they are not checking for excess
data in the RSA exponentiation result of the signature. Since there
are CAs using exponent 3 in wide use, and PKCS #1 v1.5 is used in
X.509 certificates, all software that uses OpenSSL to verify X.509
certificates is potentially vulnerable, as well as any other use of
PKCS #1 v1.5. This includes software that uses OpenSSL for SSL or TLS.
The Common Vulnerabilities and Exposures (CVE) project assigned the id
CVE-2006-4339 [2] to the problem.
________________________________________________________________________
References:
[0] http://www.openssl.org/news/secadv_20060905.txt
[1] http://www.openssl.org/
[2] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-4339
________________________________________________________________________
For security reasons, this advisory was digitally signed with the
OpenPGP public key "OpenPKG <openpkg (at) openpkg (dot) org [email concealed]>" (ID 63C4CB9F) of the
OpenPKG project which you can retrieve from http://pgp.openpkg.org and
hkp://pgp.openpkg.org. Follow the instructions on http://pgp.openpkg.org
for details on how to verify the integrity of this advisory.
________________________________________________________________________
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