CVE-2016-2105

What it actually does

Integer overflow in EVP_EncodeUpdate causes heap memory corruption when processing large binary data during base64 encoding, leading to denial of service.

Why it matters to the business

Applications relying on OpenSSL for data encoding may experience sudden crashes or service outages, disrupting operations in dependent software ecosystems with high downstream usage.

How an attack unfolds

An attacker supplies an excessively large binary payload to the vulnerable encoding function over the network, triggering the integer overflow and subsequent heap corruption that terminates the process.

How to fix it

Update OpenSSL to 1.0.1t or 1.0.2h or later; for nodejs/node apply commit 1b2bc79f96191f4a4cb268bf0048b43b2d56a284 and for phpmyadmin/phpmyadmin apply commit 243ed0268fa15567c8a787eeb6055a232102b91a.

How to confirm the fix worked

Confirm OpenSSL version is at or above the fixed releases, recompile dependent applications, and test base64 encoding functions with large inputs to verify absence of crashes.

Typical attack path

1. Identify a network-accessible service using vulnerable OpenSSL encoding routines
2. Craft and transmit a large binary data payload targeting EVP_EncodeUpdate
3. Trigger integer overflow resulting in heap corruption and process crash

How to detect it

Review application and system logs for unexpected process terminations or heap-related errors during data encoding operations; correlate with inbound network traffic containing large binary payloads.

What your security team should do

• Prioritize patching OpenSSL and listed dependents given moderate EPSS score despite age
• Inventory all products using affected OpenSSL versions for immediate upgrade
• Monitor for availability impacts until remediation is complete