Security Bulletin: Vulnerabilities in Bash affect TSSC (CVE-2014-6271, CVE-2014-7169, CVE-2014-7186, CVE-2014-7187, CVE-2014-6277, CVE-2014-6278)

Summary

Six Bash vulnerabilities were disclosed in September 2014. This bulletin addresses the vulnerabilities that have been referred to as “Bash Bug” or “Shellshock” and two memory corruption vulnerabilities. Bash is used by TSSC…

Vulnerability Details

CVE-ID: CVE-2014-6271

DESCRIPTION: GNU Bash could allow a remote attacker to execute arbitrary commands on the system, caused by an error when evaluating specially-crafted environment variables passed to it by the bash functionality. An attacker could exploit this vulnerability to write to files and execute arbitrary commands on the system.

CVSS Base Score: 10.0
CVSS Temporal Score: See http://xforce.iss.net/xforce/xfdb/96153 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:C/I:C/A:C)

CVE-ID: CVE-2014-7169

DESCRIPTION: GNU Bash could allow a remote attacker to execute arbitrary commands on the system, caused by an incomplete fix related to malformed function definitions in the values of environment variables. An attacker could exploit this vulnerability using attack vectors involving the ForceCommand feature in OpenSSH sshd, the mod_cgi and mod_cgid modules in the Apache HTTP Server to write to files and execute arbitrary commands on the system.

CVSS Base Score: 10.0
CVSS Temporal Score: See http://xforce.iss.net/xforce/xfdb/96209 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:C/I:C/A:C)

CVE-ID: CVE-2014-7186

DESCRIPTION: GNU Bash could allow a local attacker to execute arbitrary code on the system, caused by an out-of-bounds memory access while handling redir_stack. An attacker could exploit this vulnerability to execute arbitrary code on the system or cause a denial of service.

CVSS Base Score: 4.6
CVSS Temporal Score: See http://xforce.iss.net/xforce/xfdb/96237 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:L/AC:L/Au:N/C:P/I:P/A:P)

CVE-ID: CVE-2014-7187

DESCRIPTION: GNU Bash could allow a local attacker to execute arbitrary code on the system, caused by an off-by-one-error when handling deeply nested flow control constructs. An attacker could exploit this vulnerability to execute arbitrary code on the system or cause a denial of service.

CVSS Base Score: 4.6
CVSS Temporal Score: See http://xforce.iss.net/xforce/xfdb/96238 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:L/AC:L/Au:N/C:P/I:P/A:P)

CVE-2014-6277

DESCRIPTION: GNU Bash could allow a remote attacker to execute arbitrary code on the system, caused by an incomplete fix related to the failure to properly parse function definitions in the values of environment variables. An attacker could exploit this vulnerability using attack vectors involving the ForceCommand feature in OpenSSH sshd, the mod_cgi and mod_cgid modules in the Apache HTTP Server to execute arbitrary code on the system or cause a denial of service.

CVSS Base Score: 10.0
CVSS Temporal Score: See http://xforce.iss.net/xforce/xfdb/96686 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:C/I:C/A:C)

CVE-2014-6278

DESCRIPTION: GNU Bash could allow a remote attacker to execute arbitrary code on the system, caused by an incomplete fix related to the parsing of user scripts. An attacker could exploit this vulnerability to execute arbitrary code on the system or cause a denial of service.

CVSS Base Score: 10.0
CVSS Temporal Score: See http://xforce.iss.net/xforce/xfdb/96687 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:C/I:C/A:C)

Affected Products and Versions

TSSC 7.x and 5.x

Remediation/Fixes

If you are at level 7.x of the TSSC, update to TSSC 7.3.17. If you are at level 5.x, install the patch 5.12.8_shellshock. Contact IBM support to obtain fix.

Workarounds and Mitigations

No known workarounds. TSSC should be updated to the appropriate fix level…

IBM recommends that you review your entire environment to identify vulnerable releases of Bash including your Operating Systems and take appropriate mitigation and remediation actions. Please contact your Operating System provider for more information.