Chrome privilege escalation in XPCVariant::VariantDataToJS()

Chrome privilege escalation in XPCVariant::VariantDataToJS()

Announced

October 27, 2009

Reporter

moz_bug_r_a4

Impact

Critical

Products

Firefox

Fixed in

• Firefox 3.0.15
• Firefox 3.5.4

Description

Mozilla security researcher moz_bug_r_a4 reported that the XPCOM utility XPCVariant::VariantDataToJS unwrapped doubly-wrapped objects before returning them to chrome callers. This could result in chrome privileged code calling methods on an object which had previously been created or modified by web content, potentially executing malicious JavaScript code with chrome privileges.

Workaround

Disable JavaScript until a version containing these fixes can be installed.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=505988
• CVE-2009-3374