CVE-2010-4180: Medium severity OpenSSL OpenSSL vulnerability
OpenSSL before 0.9.8q, and 1.0.x before 1.0.0c, when SSLOPNETSCAPEREUSECIPHERCHANGEBUG is enabled, does not properly prevent modification of the ciphersuite in the session cache, which allows remote attackers to force the downgrade to an unintended cipher via vectors involving sniffing network traffic to discover a session identifier.
Other sources
Quoting OpenSSL security advisory:
http://openssl.org/news/secadv20101202.txt
A flaw has been found in the OpenSSL SSL/TLS server code where an old bug workaround allows malicous clients to modify the stored session cache ciphersuite. In some cases the ciphersuite can be downgraded to a weaker one on subsequent connections.
Problem affects SSL/TLS server that enable workaround for old Netscape server SSL implementation bug - SSLOPNETSCAPEREUSECIPHERCHANGEBUG. An attacker able to sniff session identifier (sent in plain during the SSL handshake) could use this flaw to force change of the cipher suite in stored session. Client, that later resumes that session, may start using different (weaker) cipher suite chosen by attacker.
OpenSSL upstream version enable SSLOPNETSCAPEREUSECIPHERCHANGEBUG when SSLOPALL option is set (it's common to set this option in applications using OpenSSL). However, OpenSSL versions in Red Hat Enterprise Linux 5 and 6 have SSLOPNETSCAPEREUSECIPHERCHANGEBUG excluded from SSLOPALL (the change was done in response to bug #175779). Applications can enable Netscape bug workaround on those versions explicitly.
OpenSSL versions prior to 0.9.8j allowed attacker to change stored session cipher quite to arbitrary cipher suite supported by OpenSSL. Version 0.9.8j corrected this issue to only allow changing cipher suite to those server is configured to use: http://cvs.openssl.org/chngview?cn=17489
In both cases, client must accept cipher suite change on resume for the downgrade attack to succeed.
Issue was addressed upstream in 0.9.8q and 1.0.0c by completely disabling this obsolete bug workaround: http://cvs.openssl.org/chngview?cn=20131
— Red Hat
Affected Software
Remediation
Patch Available
Patch Available
Patch Available
Event History
Frequently Asked Questions
What is the severity of CVE-2010-4180?
CVE-2010-4180 is classified as a high-severity vulnerability due to the potential for data interception and manipulation.
How do I fix CVE-2010-4180?
To mitigate CVE-2010-4180, upgrade OpenSSL to a version later than 0.9.8q or 1.0.0c.
What are the affected versions for CVE-2010-4180?
Affected versions include OpenSSL prior to 0.9.8q and 1.0.x before 1.0.0c.
Who can exploit CVE-2010-4180?
CVE-2010-4180 can be exploited by remote attackers who can sniff network traffic.
What does CVE-2010-4180 affect in OpenSSL?
CVE-2010-4180 affects the handling of cipher suites in the session cache allowing for potential downgrades.