Red Hat Bugzilla – Bug 1233814
CVE-2015-3237 curl: SMB send off unrelated memory contents
Last modified: 2015-07-07 08:08:41 EDT
http://curl.haxx.se/docs/adv_20150617B.html SMB send off unrelated memory contents Project cURL Security Advisory, June 17th 2015 - Permalink VULNERABILITY libcurl can get tricked by a malicious SMB server to send off data it did not intend to. In libcurl's state machine function handling the SMB protocol (smb_request_state()), two length and offset values are extracted from data that has arrived over the network, and those values are subsequently used to figure out what data range to send back. The values are used and trusted without boundary checks and are just assumed to be valid. This allows carefully handicrafted packages to trick libcurl into responding and sending off data that was not intended. Or just crash if the values cause libcurl to access invalid memory. We are not aware of any exploit of this flaw. INFO This flaw can also affect the curl command line tool if a similar operation series is made with that. The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2015-3237 to this issue. AFFECTED VERSIONS This flaw is relevant for Affected versions: libcurl 7.40.0 to and including 7.42.1 Not affected versions: libcurl < 7.40.0 and libcurl >= 7.43.0 libcurl is used by many applications, but not always advertised as such! THE SOLUTION In version 7.43.0, libcurl properly range checks the values before they are used. A patch for this problem that changes the default is available at (URL will be updated in final advisory): http://curl.haxx.se/CVE-2015-3237.patch http://curl.haxx.se/docs/adv_20150617B.html SMB send off unrelated memory contents Project cURL Security Advisory, June 17th 2015 - Permalink VULNERABILITY libcurl can get tricked by a malicious SMB server to send off data it did not intend to. In libcurl's state machine function handling the SMB protocol (smb_request_state()), two length and offset values are extracted from data that has arrived over the network, and those values are subsequently used to figure out what data range to send back. The values are used and trusted without boundary checks and are just assumed to be valid. This allows carefully handicrafted packages to trick libcurl into responding and sending off data that was not intended. Or just crash if the values cause libcurl to access invalid memory. We are not aware of any exploit of this flaw. INFO This flaw can also affect the curl command line tool if a similar operation series is made with that. The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2015-3237 to this issue. AFFECTED VERSIONS This flaw is relevant for Affected versions: libcurl 7.40.0 to and including 7.42.1 Not affected versions: libcurl < 7.40.0 and libcurl >= 7.43.0 libcurl is used by many applications, but not always advertised as such! THE SOLUTION In version 7.43.0, libcurl properly range checks the values before they are used. A patch for this problem that changes the default is available at (URL will be updated in final advisory): http://curl.haxx.se/CVE-2015-3237.patch Acknowledgements: Red Hat would like to thank curl upstream for reporting this issue. Upstream acknowledges Daniel Stenberg as the original reporter.
Created curl tracking bugs for this issue: Affects: fedora-all [bug 1233818]
curl-7.40.0-5.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.
SMB/CIFS support was added in version 7.40.0, released January 8 2015. None of the RHEL variants or ceph ship a version >7.40.0 or contain this functionality. Thus, they are not affected. Statement: This issue did not affect the versions of curl as shipped with Red Hat Enterprise Linux 5, 6, and 7, as they did not include support for SMB/CIFS.
Fedora is fixed, so we can close this.