Security Bulletin: Vulnerabilities in Python affect IBM SmartCloud Entry (CVE-2016-0772 CVE-2016-5699 CVE-2016-1000110)

Summary

IBM SmartCloud Entry is vulnerable to Python vulnerabilities. Attackers could exploit these vulnerabilities to strip out the STARTTLS command without generating an exception on the python SMTP client application and prevent the establishment of the TLS layer, inject arbitrary HTTP headers, which will allow the attacker to conduct various attacks against the vulnerable system, including cross-site scripting, cache poisoning or session hijacking, or redirect outbound HTTP traffic to arbitrary proxy server. This is also known as the “HTTPOXY” vulnerability.

Vulnerability Details

CVEID: CVE-2016-0772**
DESCRIPTION:** Python’s smtplib library is vulnerable to a stripping attack. An exception isn’t returned by the Python’s smtplib library if StartTLS fails to establish correctly in the SMTP.starttls() function. An attacker with man-in-the-middle ability could exploit this vulnerability to strip out the STARTTLS command without generating an exception on the python SMTP client application and prevent the establishment of the TLS layer.
CVSS Base Score: 6.5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/114287 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N)

CVEID: CVE-2016-5699**
DESCRIPTION:** urllib2 and urllib for Python are vulnerable to HTTP header injection, caused by improper validation of input. By persuading a victim to visit a specially-crafted Web page, a remote attacker could exploit this vulnerability to inject arbitrary HTTP headers, which will allow the attacker to conduct various attacks against the vulnerable system, including cross-site scripting, cache poisoning or session hijacking.
CVSS Base Score: 6.5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/114200 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N)

CVEID: CVE-2016-1000110**
DESCRIPTION:** Python could allow a remote attacker to redirect HTTP traffic of CGI application, caused by the failure to protect applications from the presence of untrusted client data in the HTTP_PROXY environment variable. By using a specially-crafted Proxy header in a HTTP request, an attacker could exploit this vulnerability to redirect outbound HTTP traffic to arbitrary proxy server. This is also known as the “HTTPOXY” vulnerability.
CVSS Base Score: 8.1
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/115381 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)

Affected Products and Versions

IBM SmartCloud Entry 2.2.0 through 2.2.0.4 Appliance fix pack 7
IBM SmartCloud Entry 2.3.0 through 2.3.0.4 Appliance fix pack 7
IBM SmartCloud Entry 2.4.0 through 2.4.0.4 Appliance fix pack 7
IBM SmartCloud Entry 3.1.0 through 3.1.0.4 Appliance fix pack 22
IBM SmartCloud Entry 3.2.0 through 3.2.0.4 Appliance fix pack 22

Remediation/Fixes

http://www.ibm.com/support/fixcentral/quickorder?product=ibm%2FOther+software%2FIBM+Starter+Kit+for+Cloud&fixids=2.2.0.4-IBM-SKC_APPL-FP008&source=SAR
IBM SmartCloud Entry| 2.3| None| IBM SmartCloud Entry 2.3.0 Appliance Fixpack 8:

http://www.ibm.com/support/fixcentral/quickorder?product=ibm%2FOther+software%2FIBM+SmartCloud+Entry&fixids=2.3.0.4-IBM-SCE_APPL-FP008&source=SAR
IBM SmartCloud Entry| 2.4| None| IBM SmartCloud Entry 2.4.0 Appliance Fixpack 8:

http://www.ibm.com/support/fixcentral/quickorder?product=ibm%2FOther+software%2FIBM+SmartCloud+Entry&fixids=2.4.0.4-IBM-SCE_APPL-FP008&source=SAR
IBM SmartCloud Entry| 3.1| None| IBM SmartCloud Entry 3.1.0 Appliance Fixpack 23:

http://www.ibm.com/support/fixcentral/quickorder?product=ibm%2FOther+software%2FIBM+SmartCloud+Entry&fixids=3.1.0.4-IBM-SCE_APPL-FP23&source=SAR
IBM SmartCloud Entry| 3.2| None| IBM SmartCloud Entry 3.2.0 Appliance Fixpack 23:

http://www.ibm.com/support/fixcentral/quickorder?product=ibm%2FOther+software%2FIBM+SmartCloud+Entry&fixids=3.2.0.4-IBM-SCE_APPL-FP23&source=SAR

Workarounds and Mitigations

None