CVE-2017-12361

A vulnerability in Cisco Jabber for Windows could allow an unauthenticated, local attacker to access sensitive communications made by the Jabber client. An attacker could exploit this vulnerability to gain information to conduct additional attacks. The vulnerability is due to the way Cisco Jabber for Windows handles random number generation for file folders. An attacker could exploit the vulnerability by fixing the random number data used to establish Secure Sockets Layer (SSL) connections between clients. An exploit could allow the attacker to decrypt secure communications made by the Cisco Jabber for Windows client. Cisco Bug IDs: CSCve44806.

Weakness

The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.

Affected Software

Potential Mitigations

• Use a well-vetted algorithm that is currently considered to be strong by experts in the field, and select well-tested implementations with adequate length seeds.
• In general, if a pseudo-random number generator is not advertised as being cryptographically secure, then it is probably a statistical PRNG and should not be used in security-sensitive contexts.
• Pseudo-random number generators can produce predictable numbers if the generator is known and the seed can be guessed. A 256-bit seed is a good starting point for producing a “random enough” number.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/112.html
• https://cwe.mitre.org/data/definitions/485.html
• https://cwe.mitre.org/data/definitions/59.html

References

• http://www.securityfocus.com/bid/101994
• http://www.securitytracker.com/id/1039915
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20171129-jabber2