CVE-2016-9446

The vmnc decoder in the gstreamer does not initialize the render canvas, which allows remote attackers to obtain sensitive information as demonstrated by thumbnailing a simple 1 frame vmnc movie that does not draw to the allocated render canvas.

Weakness

The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used.

Affected Software

Potential Mitigations

• Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• For example, in Java, if the programmer does not explicitly initialize a variable, then the code could produce a compile-time error (if the variable is local) or automatically initialize the variable to the default value for the variable’s type. In Perl, if explicit initialization is not performed, then a default value of undef is assigned, which is interpreted as 0, false, or an equivalent value depending on the context in which the variable is accessed.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/29.html

References

• http://www.openwall.com/lists/oss-security/2016/11/18/12
• http://www.openwall.com/lists/oss-security/2016/11/18/13
• http://www.securityfocus.com/bid/94423
• https://access.redhat.com/errata/RHSA-2017:2060
• https://bugzilla.gnome.org/show_bug.cgi?id=774533
• https://cgit.freedesktop.org/gstreamer/gst-plugins-bad/commit/gst/vmnc/vmncdec.c?id=4cb1bcf1422bbcd79c0f683edb7ee85e3f7a31fe
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UM7IXFGHV66KNWGWG6ZBDNKXD2UJL2VQ/
• https://scarybeastsecurity.blogspot.de/2016/11/0day-poc-risky-design-decisions-in.html
• https://security.gentoo.org/glsa/201705-10