Nexpose Vulnerability Database
TLS/SSL Server Supports SSLv2
Severity |
CVSS |
Published |
Added |
Modified |
|---|---|---|---|---|
| Severe (5) | 5.8 (AV:N/AC:M/Au:N/C:P/I:P/A:N) | Jan 1, 1996 | Feb 9, 2009 | Jan 28, 2011 |
Description:
Although the server accepts clients using TLS or SSLv3, it also accepts clients using SSLv2. SSLv2 is an older implementation of the Secure Sockets Layer protocol. It suffers from a number of security flaws allowing attackers to capture and alter information passed between a client and the server, including the following weaknesses:
- No protection from against man-in-the-middle attacks during the handshake.
- Weak MAC construction and MAC relying solely on the MD5 hash function.
- Exportable cipher suites unnecessarily weaken the MACs
- Same cryptographic keys used for message authentication and encryption.
- Vulnerable to truncation attacks by forged TCP FIN packets
SSLv2 has been deprecated and is no longer recommended. Note that neither SSLv2 nor SSLv3 meet the U.S. FIPS 140-2 standard, which governs cryptographic modules for use in federal information systems. Only the newer TLS (Transport Layer Security) protocol meets FIPS 140-2 requirements. In addition, the presence of an SSLv2-only service on a host is deemed a failure by the PCI (Payment Card Industry) Data Security Standard.
Note that this vulnerability will be reported when the remote server supports SSLv2 regardless of whether TLS or SSLv3 are also supported.
References:
- URL: http://www.eucybervote.org/Reports/MSI-WP2-D7V1-V1.0-02.htm
- URL: https://www.pcisecuritystandards.org/pdfs/pcissc_assessors_nl_2008-11.pdf
Solution:
Disable SSLv2 protocol support
Configure the server to require clients to use at least SSLv3 or TLS.
For Microsoft IIS web servers, see Microsoft Knowledgebase article Q187498 for instructions on disabling SSL 2.0.
For Apache web servers with mod_ssl, edit the Apache configuration file and change the SSLCipherSuite line to read:
SSLCipherSuite ALL:!ADH:RC4+RSA:+HIGH:!SSLv2
The ! (exclamation point) before SSLv2 is what disables this protocol.
Information on these pages is summary information extracted from the Nexpose Vulnerabilty Assessment system. Full details are provided within the Nexpose product for licensed users.
