CVE-2015-1283

What it actually does

Integer overflow in XML_GetBuffer leads to heap-based buffer overflow when processing crafted XML input, enabling denial of service or potential arbitrary code execution.

Why it matters to the business

Systems and applications relying on vulnerable Expat versions risk crashes or compromise when handling untrusted XML, affecting web browsers, scripting runtimes, and Linux distributions at scale.

How an attack unfolds

An attacker crafts malicious XML data that triggers the integer overflow during buffer allocation in XML_GetBuffer; the resulting heap corruption can be leveraged for denial of service or, under specific conditions, code execution in affected parsers.

How to fix it

Upgrade libexpat to a version containing the fix for CVE-2015-1283 and update all affected products (Chrome 44+, Python builds with patched Expat, and current Debian/Ubuntu/SUSE/Oracle releases) to their respective patched releases.

How to confirm the fix worked

Verify installed libexpat and dependent package versions against known fixed releases; re-test XML parsing with known-good inputs after upgrade.

Typical attack path

1. Deliver crafted XML payload to any application using a vulnerable Expat library
2. Trigger XML_GetBuffer integer overflow via specially sized input
3. Achieve heap corruption leading to denial of service or potential remote code execution

How to detect it

Review application and system logs for unexpected crashes or errors during XML parsing; correlate with network traffic containing unusual XML payloads.

What your security team should do

• Prioritize patching all internet-facing services and browsers that embed Expat
• Inventory and update downstream dependents including Python, Chrome, and Linux distributions
• Remove or isolate any remaining systems running Expat <= 2.1.0