Product Affected

STRM
Critical
9 (AV:N/AC:L/Au:N/C:C/I:P/A:P/E:P/RL:W/RC:C)

Problem



SSLv2 (Secure Socket Layer version 2) contains multiple well-known vulnerabilities that are not present in SSLv3. By default, affected versions of STRM provide SSLv2 capability; attackers can exploit the availability of SSLv2 to compromise the protocol or break the weaker encryption in SSLv2, thus compromising the confidentiality of affected traffic or allowing unauthorized access to systems.

The issue can be mitigated by disabling SSLv2, thus forcing any new connections to use the more secure SSLv3 or the equivalently secure TLSv1 (Transport Layer Security version 1) if it is available and enabled.

Solution



Fixed software is not available to resolve this issue. However, a viable workaround can be applied per the instructions shown below.

This is a zero-day issue that affects all releases of STRM.



How to obtain fixed software:

Note: At this time, fixed software is not available to fix this issue. The workaround described above is the only currently supported method of mitigating this vulnerability.

STRM Maintenance Releases and Patches are available at http://support.juniper.net/ from the "Download Software" links.

Workaround


The configuration directive "SSLProtocol" has four possible options:
  • Three protocols can be named: SSLv2, SSLv3, TLSv1, each prefixed with "+" or "-" to enable or disable the associated protocol, respectively
  • The keyword "ALL", which is an alias equivalent to "+SSLv2 +SSLv3 +TLSv1"
Thus, the option "-SSLv2" is interpreted as "disable SSLv2".

To disable SSLv2:
  1. Login as admin and enter "sudo su - root" on the STRM system.
  2. Edit the file /etc/httpd/conf.d/ssl.conf using the "vi" editor.
  3. Find the line beginning with "SSLProtocol".
  4. Modify the line to ensure that "-SSLv2" is appended to the end of the line, for example: 
            SSLProtocol all -SSLv2
    or, for another example: 
            SSLProtocol +SSLv3 +TLSv1 -SSLv2
  5. Save the file, exit from "vi", and restart the system.
Since any extant connections that were using SSLv2 will continue to do so, it is necessary to restart the system to ensure that all remaining use of SSLv2 is terminated. Following the restart, new connections will use the other available protocols.

Severity Assessment

Information for how Juniper Networks uses CVSS can be found at "KB 16446 [juniper.net] Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories".

Related Information