Mozilla Foundation Security Advisory 2012-105

Use-after-free and buffer overflow issues found using Address Sanitizer

Announced

November 20, 2012

Reporter

Abhishek Arya

Impact

Critical

Products

Firefox, Firefox ESR, SeaMonkey, Thunderbird, Thunderbird ESR

Fixed in

• Firefox 17
• Firefox ESR 10.0.11
• SeaMonkey 2.14
• Thunderbird 17
• Thunderbird ESR 10.0.11

Description

Security researcher Abhishek Arya (Inferno) of the Google Chrome Security Team discovered a series critically rated of use-after-free and buffer overflow issues using the Address Sanitizer tool in shipped software. These issues are potentially exploitable, allowing for remote code execution. We would also like to thank Abhishek for reporting five additional use-after-free, out of bounds read, and buffer overflow flaws introduced during Firefox development that were fixed before general release.

In general these flaws cannot be exploited through email in the Thunderbird and SeaMonkey products because scripting is disabled, but are potentially a risk in browser or browser-like contexts in those products.

References

The following issues were fixed in Firefox 17 and ESR 10.0.11:

• Heap-use-after-free in nsTextEditorState::PrepareEditor (CVE-2012-4214)
• Heap-use-after-free in nsPlaintextEditor::FireClipboardEvent (CVE-2012-4215)
• Heap-use-after-free in gfxFont::GetFontEntry (CVE-2012-4216)
• heap-buffer-overflow in gfxShapedWord::CompressedGlyph::IsClusterStart - CVE-2012-5839
• Heap-use-after-free in nsTextEditorState::PrepareEditor (CVE-2012-5840)

The following issues were fixed in Firefox 17:

• Heap-use-after-free in XPCWrappedNative::Mark (CVE-2012-4212)
• Heap-use-after-free in nsEditor::FindNextLeafNode (CVE-2012-4213)
• Heap-use-after-free in nsViewManager::ProcessPendingUpdates (CVE-2012-4217)
• Heap-use-after-free BuildTextRunsScanner::BreakSink::SetBreaks (CVE-2012-4218)