CVE-2015-4497

What it actually does

Use-after-free in CanvasRenderingContext2D triggered by resize events interacting with CSS token sequence changes on a CANVAS element, enabling arbitrary code execution.

Why it matters to the business

Attackers can run malicious code on affected systems, leading to full compromise, data theft, or service disruption; the issue affects older browser versions still in limited use despite being years old.

How an attack unfolds

An attacker crafts a malicious web page containing a CANVAS element with specific CSS and resize event handlers that trigger the use-after-free condition, allowing memory corruption and code execution in the browser process.

How to fix it

Upgrade radare2 to version 1.1.0+dfsg-3 or later on Debian 13 systems and apply commit ad55822430a03fe075221b543efb434567e9e431 or newer for GIT builds; replace any embedded or bundled older Firefox components if present.

How to confirm the fix worked

Verify installed package versions match or exceed the listed fixed releases using package managers or build logs; test affected CANVAS functionality in updated browser or component builds to confirm absence of the crash condition.

Typical attack path

1. Host malicious page on attacker-controlled site or compromised legitimate site
2. Lure victim to visit the page via phishing or malvertising
3. Page loads CANVAS element and manipulates CSS tokens while triggering resize events
4. Use-after-free occurs leading to memory corruption and shellcode execution

How to detect it

Review web server access logs and browser crash reports for visits to suspicious pages with heavy CANVAS manipulation; examine memory dumps or process crashes around resize and CSS events in older browser instances.

What your security team should do

• Prioritize updating all radare2 instances to the specified fixed versions immediately
• Scan internal repositories and build pipelines for older radare2 or affected Firefox dependencies
• Monitor for any remaining instances of vulnerable versions through asset inventory