Out-of-bounds read in HTML parser following a failed allocation

Out-of-bounds read in HTML parser following a failed allocation

Announced

March 8, 2016

Reporter

Ronald Crane

Impact

High

Products

Firefox, Firefox ESR, Thunderbird

Fixed in

• Firefox 45
• Firefox ESR 38.7
• Thunderbird 38.7
• Thunderbird 45

Description

Security researcher Ronald Crane reported an out-of-bounds read following a failed allocation in the HTML parser while working with unicode strings. This can also affect the parsing of XML and SVG format data. This leads to a potentially exploitable crash.

In general this flaw cannot be exploited through email in the Thunderbird product because scripting is disabled, but is potentially a risk in browser or browser-like contexts.

References

• Lack of status return from nsScannerString::AppendUnicodeTo causes out-of-bounds read in AppendErrorPointer (CVE-2016-1974)