RHSA-2016:0996 - Security Advisory

Topic

An update for openssl is now available for Red Hat Enterprise Linux 6.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

OpenSSL is a toolkit that implements the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols, as well as a full-strength general-purpose cryptography library.

Security Fix(es):

• A flaw was found in the way OpenSSL encoded certain ASN.1 data structures. An attacker could use this flaw to create a specially crafted certificate which, when verified or re-encoded by OpenSSL, could cause it to crash, or execute arbitrary code using the permissions of the user running an application compiled against the OpenSSL library. (CVE-2016-2108)
• Two integer overflow flaws, leading to buffer overflows, were found in the way the EVP_EncodeUpdate() and EVP_EncryptUpdate() functions of OpenSSL parsed very large amounts of input data. A remote attacker could use these flaws to crash an application using OpenSSL or, possibly, execute arbitrary code with the permissions of the user running that application. (CVE-2016-2105, CVE-2016-2106)
• It was discovered that OpenSSL leaked timing information when decrypting TLS/SSL and DTLS protocol encrypted records when the connection used the AES CBC cipher suite and the server supported AES-NI. A remote attacker could possibly use this flaw to retrieve plain text from encrypted packets by using a TLS/SSL or DTLS server as a padding oracle. (CVE-2016-2107)
• Several flaws were found in the way BIO_*printf functions were implemented in OpenSSL. Applications which passed large amounts of untrusted data through these functions could crash or potentially execute code with the permissions of the user running such an application. (CVE-2016-0799, CVE-2016-2842)
• A denial of service flaw was found in the way OpenSSL parsed certain ASN.1-encoded data from BIO (OpenSSL's I/O abstraction) inputs. An application using OpenSSL that accepts untrusted ASN.1 BIO input could be forced to allocate an excessive amount of data. (CVE-2016-2109)

Red Hat would like to thank the OpenSSL project for reporting CVE-2016-2108, CVE-2016-2842, CVE-2016-2105, CVE-2016-2106, CVE-2016-2107, and CVE-2016-0799. Upstream acknowledges Huzaifa Sidhpurwala (Red Hat), Hanno Böck, and David Benjamin (Google) as the original reporters of CVE-2016-2108; Guido Vranken as the original reporter of CVE-2016-2842, CVE-2016-2105, CVE-2016-2106, and CVE-2016-0799; and Juraj Somorovsky as the original reporter of CVE-2016-2107.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

For the update to take effect, all services linked to the OpenSSL library must be restarted, or the system rebooted.

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 1312219 - CVE-2016-0799 OpenSSL: Fix memory issues in BIO_*printf functions
• BZ - 1314757 - CVE-2016-2842 openssl: doapr_outch function does not verify that certain memory allocation succeeds
• BZ - 1330101 - CVE-2016-2109 openssl: ASN.1 BIO handling of large amounts of data
• BZ - 1331402 - CVE-2016-2108 openssl: Memory corruption in the ASN.1 encoder
• BZ - 1331426 - CVE-2016-2107 openssl: Padding oracle in AES-NI CBC MAC check
• BZ - 1331441 - CVE-2016-2105 openssl: EVP_EncodeUpdate overflow
• BZ - 1331536 - CVE-2016-2106 openssl: EVP_EncryptUpdate overflow

CVEs

• CVE-2016-0799
• CVE-2016-2105
• CVE-2016-2106
• CVE-2016-2107
• CVE-2016-2108
• CVE-2016-2109
• CVE-2016-2842

References

• http://www.redhat.com/security/updates/classification/#normal