verify.c in GnuTLS before 1.4.4, when using an RSA key with exponent 3, does not properly handle excess data in the digestAlgorithm.parameters field when generating a hash, which allows remote attackers to forge a PKCS #1 v1.5 signature that is signed by that RSA key and prevents GnuTLS from correctly verifying X.509 and other certificates that use PKCS, a variant of CVE-2006-4339.

GNOME 2.6.0_x86: GNU Transport Layer Security Library Patch.
Date this patch was last updated by Sun : Oct/17/16

GNOME 2.6.0_x86: GNU Transport Layer Security Library Patch.
Date this patch was last updated by Sun : Nov/15/14

GNOME 2.6.0_x86: GNU Transport Layer Security Library Patch.
Date this patch was last updated by Sun : Sep/13/14

GNOME 2.6.0: GNU Transport Layer Security Library Patch.
Date this patch was last updated by Sun : Oct/17/16

GNOME 2.6.0: GNU Transport Layer Security Library Patch.
Date this patch was last updated by Sun : Nov/15/14

GNOME 2.6.0: GNU Transport Layer Security Library Patch.
Date this patch was last updated by Sun : Sep/13/14

From Red Hat Security Advisory 2006:0680 :

Updated gnutls packages that fix a security issue are now available for Red Hat Enterprise Linux 4.

This update has been rated as having important security impact by the Red Hat Security Response Team.

The GnuTLS Library provides support for cryptographic algorithms and protocols such as TLS. GnuTLS includes libtasn1, a library developed for ASN.1 structures management that includes DER encoding and decoding.

Daniel Bleichenbacher recently described an attack on PKCS #1 v1.5 signatures. Where an RSA key with exponent 3 is used it may be possible for an attacker to forge a PKCS #1 v1.5 signature that would be incorrectly verified by implementations that do not check for excess data in the RSA exponentiation result of the signature.

The core GnuTLS team discovered that GnuTLS is vulnerable to a variant of the Bleichenbacker attack. This issue affects applications that use GnuTLS to verify X.509 certificates as well as other uses of PKCS #1 v1.5. (CVE-2006-4790)

In Red Hat Enterprise Linux 4, the GnuTLS library is only used by the Evolution client when connecting to an Exchange server or when publishing calendar information to a WebDAV server.

Users are advised to upgrade to these updated packages, which contain a backported patch from the GnuTLS maintainers to correct this issue.

A security problem in the GNU TLS library has been found :

If an RSA key with exponent 3 is used, the PKCS padding gets removed before generating a hash, which allows remote attackers to forge a PKCS signature that apapears to be signed by that RSA key and prevents gnutls from correctly verifying the certificate.

This bug has been tracked by the Mitre CVE ID CVE-2006-4790.

This update brings IBM Java 1.4.2 to Service Release 7.

It contains several undisclosed security fixes, including the fix for the RSA attack similar to Mitre CVE ID CVE-2006-4790.

It also contains timezone updates :

  - US daylightsaving time update starting 2007.

  - Western Australia daylight savings time introduction in     December 2006.

  - Update to current timezone dataset.

A security problem was fixed in the GNU TLS library, where excess data was not checked during signature checking with RSA keys with exponent 3.

This problem could be used to fake those RSA signatures.
(CVE-2006-4790)

The GnuTLS library did not sufficiently check the padding of PKCS #1 v1.5 signatures if the exponent of the public key is 3 (which is widely used for CAs). This could be exploited to forge signatures without the need of the secret key.

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

verify.c in GnuTLS before 1.4.4, when using an RSA key with exponent 3, does not properly handle excess data in the digestAlgorithm.parameters field when generating a hash, which allows remote attackers to forge a PKCS #1 v1.5 signature that is signed by that RSA key and prevents GnuTLS from correctly verifying X.509 and other certificates that use PKCS, a variant of CVE-2006-4339.

The provided packages have been patched to correct this issues.

Daniel Bleichenbacher discovered a flaw in GNU TLS cryptographic package that could allow an attacker to generate a forged signature that GNU TLS will accept as valid.

Secunia reports :

A vulnerability has been reported in GnuTLS, which can be exploited by malicious people to bypass certain security restrictions.

The vulnerability is caused due to an error in the verification of certain signatures. If a RSA key with exponent 3 is used, it may be possible to forge PKCS #1 v1.5 signatures signed with that key.

The remote host is affected by the vulnerability described in GLSA-200609-15 (GnuTLS: RSA Signature Forgery)

    verify.c fails to properly handle excess data in     digestAlgorithm.parameters field while generating a hash when using an     RSA key with exponent 3. RSA keys that use exponent 3 are commonplace.
  Impact :

    Remote attackers could forge PKCS #1 v1.5 signatures that are signed     with an RSA key, preventing GnuTLS from correctly verifying X.509 and     other certificates that use PKCS.
  Workaround :

    There is no known workaround at this time.

Updated gnutls packages that fix a security issue are now available for Red Hat Enterprise Linux 4.

This update has been rated as having important security impact by the Red Hat Security Response Team.

The GnuTLS Library provides support for cryptographic algorithms and protocols such as TLS. GnuTLS includes libtasn1, a library developed for ASN.1 structures management that includes DER encoding and decoding.

Daniel Bleichenbacher recently described an attack on PKCS #1 v1.5 signatures. Where an RSA key with exponent 3 is used it may be possible for an attacker to forge a PKCS #1 v1.5 signature that would be incorrectly verified by implementations that do not check for excess data in the RSA exponentiation result of the signature.

The core GnuTLS team discovered that GnuTLS is vulnerable to a variant of the Bleichenbacker attack. This issue affects applications that use GnuTLS to verify X.509 certificates as well as other uses of PKCS #1 v1.5. (CVE-2006-4790)

In Red Hat Enterprise Linux 4, the GnuTLS library is only used by the Evolution client when connecting to an Exchange server or when publishing calendar information to a WebDAV server.

Users are advised to upgrade to these updated packages, which contain a backported patch from the GnuTLS maintainers to correct this issue.

ID	Name	Product	Family	Severity
107902	Solaris 10 (x86) : 123939-05	Nessus	Solaris Local Security Checks	medium
107901	Solaris 10 (x86) : 123939-04	Nessus	Solaris Local Security Checks	medium
107900	Solaris 10 (x86) : 123939-03	Nessus	Solaris Local Security Checks	medium
107399	Solaris 10 (sparc) : 123938-05	Nessus	Solaris Local Security Checks	medium
107398	Solaris 10 (sparc) : 123938-04	Nessus	Solaris Local Security Checks	medium
107397	Solaris 10 (sparc) : 123938-03	Nessus	Solaris Local Security Checks	medium
67410	Oracle Linux 4 : gnutls (ELSA-2006-0680)	Nessus	Oracle Linux Local Security Checks	medium
41101	SuSE9 Security Update : gnutls (YOU Patch Number 11228)	Nessus	SuSE Local Security Checks	medium
29468	SuSE 10 Security Update : IBM Java (ZYPP Patch Number 2461)	Nessus	SuSE Local Security Checks	medium
29447	SuSE 10 Security Update : gnutls (ZYPP Patch Number 2117)	Nessus	SuSE Local Security Checks	medium
27928	Ubuntu 5.04 / 5.10 / 6.06 LTS : gnutls11, gnutls12 vulnerability (USN-348-1)	Nessus	Ubuntu Local Security Checks	medium
27242	openSUSE 10 Security Update : gnutls (gnutls-2118)	Nessus	SuSE Local Security Checks	medium
24552	Mandrake Linux Security Advisory : gnutls (MDKSA-2006:166)	Nessus	Mandriva Local Security Checks	medium
22724	Debian DSA-1182-1 : gnutls11 - cryptographic weakness	Nessus	Debian Local Security Checks	medium
22501	FreeBSD : gnutls -- RSA Signature Forgery Vulnerability (64bf6234-520d-11db-8f1a-000a48049292)	Nessus	FreeBSD Local Security Checks	medium
22459	GLSA-200609-15 : GnuTLS: RSA Signature Forgery	Nessus	Gentoo Local Security Checks	medium
22427	CentOS 4 : gnutls (CESA-2006:0680)	Nessus	CentOS Local Security Checks	medium
22360	RHEL 4 : gnutls (RHSA-2006:0680)	Nessus	Red Hat Local Security Checks	medium

Detections

Analytics

CVE-2006-4790

high

Tenable Plugins

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium