Security Bulletin: Vulnerabilities in OpenSSL including Logjam affect IBM Tivoli Composite Application Manager for Transactions (CVE-2015-1788, CVE-2015-1789, CVE-2015-1791, CVE-2015-4000)

Summary

OpenSSL vulnerabilities were disclosed on June 11, 2015 by the OpenSSL Project. This includes Logjam Attack on TLS connections using the Diffie-Hellman (DH) key exchange protocol (CVE-2015-4000). OpenSSL is used by IBM Tivoli Composite Application Manager for Transactions. IBM Tivoli Composite Application Manager for Transactions has addressed the applicable CVEs.

Vulnerability Details

CVEID: CVE-2015-4000**
DESCRIPTION:** The TLS protocol could allow a remote attacker to obtain sensitive information, caused by the failure to properly convey a DHE_EXPORT ciphersuite choice. An attacker could exploit this vulnerability using man-in-the-middle techniques to force a downgrade to 512-bit export-grade cipher. Successful exploitation could allow an attacker to recover the session key as well as modify the contents of the traffic. This vulnerability is commonly referred to as “Logjam”.
CVSS Base Score: 4.3
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/103294 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:M/Au:N/C:P/I:N/A:N)

CVEID: CVE-2015-1788 DESCRIPTION: OpenSSL is vulnerable to a denial of service, caused by an error when processing an ECParameters structure over a specially crafted binary polynomial field. A remote attacker could exploit this vulnerability to cause the application to enter into an infinite loop.
CVSS Base Score: 5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/#/vulnerabilities/103778 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:N/I:N/A:P)

CVEID: CVE-2015-1789 DESCRIPTION: OpenSSL is vulnerable to a denial of service, caused by an out-of-bounds read in X509_cmp_time. An attacker could exploit this vulnerability using a specially crafted certificate or CRL to trigger a segmentation fault.
CVSS Base Score: 5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/#/vulnerabilities/103779 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:N/I:N/A:P)

CVEID: CVE-2015-1791 DESCRIPTION: A double-free memory error in OpenSSL in the ssl3_get_new_session_ticket() function has an unknown impact. By returning a specially crafted NewSessionTicket message, an attacker could cause the client to reuse a previous ticket resulting in a race condition.
CVSS Base Score: 5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/#/vulnerabilities/103609 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:N/I:P/A:N)

Affected Products and Versions

IBM Tivoli Composite Application Manager (ITCAM) for Transactions is affected. ITCAM for Transactions contains multiple sub components (Agents). Only the Internet Service Monitor (ISM – Agent code ‘IS’) is affected.

Versions:

· 7.4 – Affected by CVE (CVE-2015-1788, CVE-2015-1789, CVE-2015-1791 and CVE-2015-4000)

· 7.3 – Affected by CVE (CVE-2015-1788, CVE-2015-1789, CVE-2015-1791 and CVE-2015-4000)

Remediation/Fixes

Product

| VRMF| APAR| Remediation/First Fix
—|—|—|—
7.4.0.0-TIV-CAMIS-FP0001| 7.4.0.1| None| http://www.ibm.com/support/docview.wss?uid=isg400002269
7.3.0.1-TIV-CAMIS-IF0036| 7.3.0.1| None| http://www-01.ibm.com/support/docview.wss?rs=0&uid=isg400002358

For CVE-2015-4000: As the length of the server key size are increased, the amount of CPU required for full TLS/SSL handshake can significantly increase. Please carefully test and assess the impact to your CPU requirements to ensure sufficient CPU resources, otherwise the system availability may be impacted.

For CVE-2015-4000: You should verify applying this configuration change does not cause any compatibility issues. If you change the default setting after applying the fix, you will expose yourself to the attack described above. IBM recommends that you review your entire environment to identify other areas where you have enabled the Diffie-Hellman key-exchange protocol used in TLS and take appropriate mitigation and remediation actions.

For ISM 7.1 and 7.2 IBM recommends upgrading to a fixed, supported version/release/platform of the productAdded th.

Workarounds and Mitigations

For CVE-2015-4000, ISM disable the DHE/EDH ciphers in all monitors. To disable the DHE/EDH ciphers, update the monitor properties: SSLCipherSuite and BridgeSSLCipherSet. For example, to disable DHE/EDH ciphers in the HTTPS monitor, update the https.props file to include

SSLCipherSuite : “AES:3DES:DES:!EXP:!DHE:!EDH”
BridgeSSLCipherSet : “AES:3DES:DES:!EXP:!DHE:!EDH”

For CVE-2015-4000: You should verify applying this configuration change does not cause any compatibility issues. If you change the default setting after applying the fix, you will expose yourself to the attack described above. IBM recommends that you review your entire environment to identify other areas where you have enabled the Diffie-Hellman key-exchange protocol used in TLS and take appropriate mitigation and remediation actions.