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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2012.0027 Six security flaws have been fixed in OpenSSL 1.0.0f and 0.9.8s 5 January 2012 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: OpenSSL Publisher: OpenSSL Operating System: UNIX variants (UNIX, Linux, OSX) Windows Impact/Access: Execute Arbitrary Code/Commands -- Remote/Unauthenticated Access Privileged Data -- Remote/Unauthenticated Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2012-0027 CVE-2011-4619 CVE-2011-4577 CVE-2011-4576 CVE-2011-4109 CVE-2011-4108 Original Bulletin: http://www.openssl.org/news/secadv_20120104.txt - --------------------------BEGIN INCLUDED TEXT-------------------- OpenSSL Security Advisory [04 Jan 2012] ======================================= Six security flaws have been fixed in OpenSSL 1.0.0f and 0.9.8s. DTLS Plaintext Recovery Attack (CVE-2011-4108) ============================================== Nadhem Alfardan and Kenny Paterson have discovered an extension of the Vaudenay padding oracle attack on CBC mode encryption which enables an efficient plaintext recovery attack against the OpenSSL implementation of DTLS. Their attack exploits timing differences arising during decryption processing. A research paper describing this attack can be found at http://www.isg.rhul.ac.uk/~kp/dtls.pdf Thanks go to Nadhem Alfardan and Kenny Paterson of the Information Security Group at Royal Holloway, University of London (www.isg.rhul.ac.uk) for discovering this flaw and to Robin Seggelmann <seggelmann@fh-muenster.de> and Michael Tuexen <tuexen@fh-muenster.de> for preparing the fix. Affected users should upgrade to OpenSSL 1.0.0f or 0.9.8s. Double-free in Policy Checks (CVE-2011-4109) ============================================ If X509_V_FLAG_POLICY_CHECK is set in OpenSSL 0.9.8, then a policy check failure can lead to a double-free. The bug does not occur unless this flag is set. Users of OpenSSL 1.0.0 are not affected. This flaw was discovered by Ben Laurie and a fix provided by Emilia Kasper <ekasper@google.com> of Google. Affected users should upgrade to OpenSSL 0.9.8s. Uninitialized SSL 3.0 Padding (CVE-2011-4576) ============================================= OpenSSL prior to 1.0.0f and 0.9.8s failed to clear the bytes used as block cipher padding in SSL 3.0 records. This affects both clients and servers that accept SSL 3.0 handshakes: those that call SSL_CTX_new with SSLv3_{server|client}_method or SSLv23_{server|client}_method. It does not affect TLS. As a result, in each record, up to 15 bytes of uninitialized memory may be sent, encrypted, to the SSL peer. This could include sensitive contents of previously freed memory. However, in practice, most deployments do not use SSL_MODE_RELEASE_BUFFERS and therefore have a single write buffer per connection. That write buffer is partially filled with non-sensitive, handshake data at the beginning of the connection and, thereafter, only records which are longer any any previously sent record leak any non-encrypted data. This, combined with the small number of bytes leaked per record, serves to limit to severity of this issue. Thanks to Adam Langley <agl@chromium.org> for identifying and fixing this issue. Affected users should upgrade to OpenSSL 1.0.0f or 0.9.8s. Malformed RFC 3779 Data Can Cause Assertion Failures (CVE-2011-4577) ==================================================================== RFC 3779 data can be included in certificates, and if it is malformed, may trigger an assertion failure. This could be used in a denial-of-service attack. Note, however, that in the standard release of OpenSSL, RFC 3779 support is disabled by default, and in this case OpenSSL is not vulnerable. Builds of OpenSSL are vulnerable if configured with "enable-rfc3779". Thanks to Andrew Chi, BBN Technologies, for discovering the flaw, and Rob Austein <sra@hactrn.net> for fixing it. Affected users should upgrade to OpenSSL 1.0.0f or 0.9.8s. SGC Restart DoS Attack (CVE-2011-4619) ====================================== Support for handshake restarts for server gated cryptograpy (SGC) can be used in a denial-of-service attack. Thanks to Adam Langley <agl@chromium.org> for identifying and fixing this issue. Affected users should upgrade to OpenSSL 1.0.0f or 0.9.8s. Invalid GOST parameters DoS Attack (CVE-2012-0027) =================================================== A malicious TLS client can send an invalid set of GOST parameters which will cause the server to crash due to lack of error checking. This could be used in a denial-of-service attack. Only users of the OpenSSL GOST ENGINE are affected by this bug. Thanks to Andrey Kulikov <amdeich@gmail.com> for identifying and fixing this issue. Affected users should upgrade to OpenSSL 1.0.0f. References ========== URL for this Security Advisory: http://www.openssl.org/news/secadv_20120104.txt - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBTwUlF+4yVqjM2NGpAQKbqxAAtNvcdbKUSv+gz9ckmBTPZbXNOFLV+yQU KwavBdxAA7C0UKgKihWYOOt6r9y4RTLH3/HoZw9+zMgh2KyA2R4I9U+g3UpcyhnF ekhvPNbrcGCVO/kul3wlToLTMV/OCnexCQfcslTtOmdQK6M7q2mYhaXDYlyN2MGC Mj4fMBQyjQ9VljiSVgycHqVHmKOLCOimmZg32iKqetHAKDFfG034oYbKq9hqMhae /zyF8wgG84zmsx0o/ovmJMruE0pqmtl8/TeZgbPMot8vHPVbVCt2ONEqrg27P4rs zvTW9nKNp5oJcYMUlirsxGVZ9vEZJX4baNKb++Y+M1k5wTlfcYmfQaFLRWN1zgpr DexnpXxsiDzx5PruZpAkaHIch0EfyMg02nKmFjCUMVDXww+l0nsz0nfIK/TOSQJo ZokyFIXIheB+NCtk9Pdb1AUMlzi6W/wyBpiIqcpbnMn/ASZMbuXgIEefmv98QxYs 6qWBqJcgiWs2EZbd+Z+yzl2O6kn6eEZAsYYjnlnmO09pMtJmzUf2OtIfTUJ5qG2p PFAlGdENEWJ2ghuLnFeE/JF7rn07fl1Z3RZHwC/VsRlNBK8hfPEC6++6rQ965g+A 5Qrs6FwZyzC9GNBzItUikLtPRGqRWZqgxqfVYZlIYEDdxcsUWHtwVQkBFfXy4dYD rtKbV++8ViQ= =aQQO -----END PGP SIGNATURE-----