CVE-2015-0801

What it actually does

Bypasses the Same Origin Policy to permit remote execution of arbitrary JavaScript code with chrome privileges through specially crafted anchor navigation.

Why it matters to the business

Attackers can steal user data, hijack sessions, or install malware on systems still running these legacy browser versions, increasing breach risk and potential regulatory exposure for organizations that have not retired or upgraded the affected software.

How an attack unfolds

An attacker hosts a malicious page containing crafted anchor links; when a victim navigates the links, the Same Origin Policy check is evaded, allowing JavaScript to run with elevated chrome privileges and perform unauthorized actions.

How to fix it

Upgrade Mozilla Firefox to version 37.0 or later, Firefox ESR to 31.6 or later, and Thunderbird to 31.6 or later; remove or isolate any remaining instances of the vulnerable versions.

How to confirm the fix worked

Inventory all browser installations and confirm running versions are at or above the fixed releases; test that Same Origin Policy enforcement behaves correctly on anchor navigation in updated builds.

Typical attack path

1. Attacker prepares malicious webpage with crafted anchor navigation vectors
2. Victim is lured to visit the page via phishing or compromised site
3. Anchor navigation triggers the Same Origin Policy bypass
4. Arbitrary JavaScript executes with chrome privileges
5. Attacker performs actions such as data exfiltration or further compromise

How to detect it

Review web proxy and browser logs for unusual navigation patterns involving anchor elements from untrusted origins; examine process execution for JavaScript activity with elevated privileges on affected legacy versions.

What your security team should do

• Prioritize immediate upgrade of all Firefox, Firefox ESR, and Thunderbird instances to the fixed versions
• Block or restrict legacy browser usage through enterprise policy or network controls
• Monitor for continued use of unpatched versions and accelerate decommissioning of end-of-life software