X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/28409cd358d5ff17e2c340298988e8baf86fd5f5..33b39968948f2dcda5c073916d797259e441d1de:/doc/security.mdwn

diff --git a/doc/security.mdwn b/doc/security.mdwn
index 4f825deba..317a534ca 100644
--- a/doc/security.mdwn
+++ b/doc/security.mdwn
@@ -561,5 +561,32 @@ result in `policy.mdwn` being altered.
 This affects sites with the `git` VCS and the `recentchanges` plugin,
 which are both used in most ikiwiki installations.
 
-This bug was reported on 2016-12-17. The fixed version 3.20161219
-was released on 2016-12-19. ([[!cve CVE-2016-10026]])
+This bug was reported on 2016-12-17. A partially fixed version
+3.20161219 was released on 2016-12-19, but the solution used in that
+version was not effective with git versions older than 2.8.0.
+
+([[!cve CVE-2016-10026]] represents the original vulnerability.
+[[!cve CVE-2016-9645]]/OVE-20161226-0002 represents the vulnerability
+in 3.20161219 caused by the incomplete fix.)
+
+## Commit metadata forgery via CGI::FormBuilder context-dependent APIs
+
+When CGI::FormBuilder->field("foo") is called in list context (and
+in particular in the arguments to a subroutine that takes named
+arguments), it can return zero or more values for foo from the CGI
+request, rather than the expected single value. This breaks the usual
+Perl parsing convention for named arguments, similar to CVE-2014-1572
+in Bugzilla (which was caused by a similar API design issue in CGI.pm).
+
+In ikiwiki, this appears to have been exploitable in two places, both
+of them relatively minor:
+
+* in the comments plugin, an attacker who was able to post a comment
+  could give it a user-specified author and author-URL even if the wiki
+  configuration did not allow for that, by crafting multiple values
+  for other fields
+* in the editpage plugin, an attacker who was able to edit a page
+  could potentially forge commit authorship (attribute their edit to
+  someone else) by crafting multiple values for the rcsinfo field
+
+([[!cve CVE-2016-9646]]/OVE-20161226-0001)