CVE-2014-0138

libcurl can in some circumstances reuse the wrong connection when asked to do transfers using other protocols than HTTP and FTP.

libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead.

When reusing a connection a range of criterion must first be met. Due to an error in the code, a transfer that was initiated by an application could wrongfully reuse an existing connection to the same server that was authenticated using different credentials. The existing logic only worked well enough for HTTP and FTP, while all other network protocols were silently, but erroneously, assumed to work like HTTP. Protocols that use connection oriented authentication need a new connection when new credentials are used.

Affected protocols include: SCP, SFTP, POP3(S), IMAP(S), SMTP(S) and LDAP(S).

Applications can disable libcurl's reuse of connections and thus mitigate this problem, by using one of the following libcurl options to alter how connections are or are not reused: CURLOPT_FRESH_CONNECT, CURLOPT_MAXCONNECTS and CURLMOPT_MAX_HOST_CONNECTIONS (if using the curl_multi API).

(This problem is similar to a problem previously reported to NTLM HTTP connections, named CVE-2014-0015)

The default configuration in cURL and libcurl 7.10.6 before 7.36.0 re-uses (1) SCP, (2) SFTP, (3) POP3, (4) POP3S, (5) IMAP, (6) IMAPS, (7) SMTP, (8) SMTPS, (9) LDAP, and (10) LDAPS connections, which might allow context-dependent attackers to connect as other users via a request, a similar issue to CVE-2014-0015.

The default configuration in cURL and libcurl 7.10.6 before 7.36.0 re-uses (1) SCP, (2) SFTP, (3) POP3, (4) POP3S, (5) IMAP, (6) IMAPS, (7) SMTP, (8) SMTPS, (9) LDAP, and (10) LDAPS connections, which might allow context-dependent attackers to connect as other users via a request, a similar issue to CVE-2014-0015.

Updated curl packages fix security vulnerabilities:

Paras Sethia discovered that libcurl would sometimes mix up multiple HTTP and HTTPS connections with NTLM authentication to the same server, sending requests for one user over the connection authenticated as a different user (CVE-2014-0015).

libcurl can in some circumstances re-use the wrong connection when asked to do transfers using other protocols than HTTP and FTP, causing a transfer that was initiated by an application to wrongfully re-use an existing connection to the same server that was authenticated using different credentials (CVE-2014-0138).

libcurl incorrectly validates wildcard SSL certificates containing literal IP addresses, so under certain conditions, it would allow and use a wildcard match specified in the CN field, allowing a malicious server to participate in a MITM attack or just fool users into believing that it is a legitimate site (CVE-2014-0139).

These are all security issues fixed in the curl-7.51.0-1.1 package on the GA media of openSUSE Tumbleweed.

This curl update fixes the following security issues:

* bnc#868627: wrong re-use of connections (CVE-2014-0138).
* bnc#868629: IP address wildcard certificate validation
  (CVE-2014-0139).
* bnc#870444: --insecure option inappropriately enforcing security
  safeguard.

Security Issue references:

* CVE-2014-0138
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-0138>
* CVE-2014-0139
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-0139>