OpenSSL Multiple Vulnerabilities

SA47426

CVE-2011-4108, CVE-2011-4109, CVE-2011-4576, CVE-2011-4577, CVE-2011-4619, CVE-2012-0027

05 Jan 2012

Moderately Critical

Vendor Patch

OpenSSL 0.x
OpenSSL 1.x

From remote

DoS (Denial of Service)

This includes vulnerabilities ranging from excessive resource consumption (e.g. causing a system to use a lot of memory) to crashing an application or an entire system.

System access

This covers vulnerabilities where malicious people are able to gain system access and execute arbitrary code with the privileges of a local user.

Exposure of sensitive information

Vulnerabilities where documents or credentials are leaked or can be revealed either locally or from remote.

Multiple vulnerabilities have been reported in OpenSSL, which can be exploited by malicious people to disclose potentially sensitive information, cause a DoS (Denial of Service), and potentially compromise an application using the library.

1) The CBC mode encryption of Datagram Transport Layer Security (DTLS) exposes timing differences during the decryption process, which can be exploited to recover the plaintext via a Vaudenay padding oracle attack extension.

2) A double-free error exists within the policy checks if X509_V_FLAG_POLICY_CHECK is used.

Note: This vulnerability does not affect version 1.0.0 and later.

3) The library does not properly clear the block cipher padding in SSL 3.0 records, which may lead to 15 bytes of uninitialised memory containing potentially sensitive information being encrypted and sent to the SSL peer.

4) An error within the handling of malformed RFC 3779 data in certificates can be exploited to cause assertion errors.

Successful exploitation of this vulnerability requires that OpenSSL is configured with "enable-rfc3779" (disabled by default).

5) An error within the handshake restart handling for Server Gated Cryptograpy (SGC) can be exploited to cause a DoS.

6) An error within the GOST ENGINE when processing invalid GOST parameters can be exploited by a TLS client to cause a crash the server by sending specially crafted GOST parameters.

Update to version 0.9.8s or 1.0.0f.
http://www.openssl.org/source/

1) Nadhem Alfardan and Kenny Paterson, Information Security Group at Royal Holloway, University of London

The vendor credits:
2) Ben Laurie
3, 5) Adam Langley
4) Andrew Chi, BBN Technologies
6) Andrey Kulikov

OpenSSL Security Advisory [04 Jan 2012]:
http://openssl.org/news/secadv_20120104.txt