CVE-2014-9911

What it actually does

Stack-based buffer overflow in ures_getByKeyWithFallback triggered by malformed input to uloc_getDisplayName, enabling memory corruption that can lead to denial of service or arbitrary code execution.

Why it matters to the business

Applications relying on ICU for text and locale processing face risk of crashes, unauthorized code execution, or full system compromise, potentially disrupting services and exposing sensitive data across internationalized software ecosystems.

How an attack unfolds

An attacker identifies a target application using a vulnerable ICU version and supplies a crafted locale string via uloc_getDisplayName, overflowing the stack buffer in ures_getByKeyWithFallback to corrupt memory and achieve code execution or denial of service.

How to fix it

Upgrade International Components for Unicode (ICU) to version 54.1 or later; rebuild and redeploy dependent applications after the update.

How to confirm the fix worked

Verify ICU library version is 54.1 or higher via package managers or build manifests; recompile applications and test locale display functions with boundary inputs to confirm absence of overflow behavior.

Typical attack path

1. Scan for services or libraries exposing ICU locale functions
2. Craft and deliver malicious input to uloc_getDisplayName
3. Trigger stack overflow in ures_getByKeyWithFallback
4. Leverage memory corruption for code execution or crash

How to detect it

Review application logs for unexpected crashes or errors during locale name processing; examine process memory dumps for signs of stack corruption around ICU locale functions; correlate with network traffic containing unusual locale strings.

What your security team should do

• Prioritize upgrade of ICU across all affected products due to high CVSS and remote exploitability
• Inventory applications and dependencies using ICU to identify exposure
• Implement input validation or sandboxing around locale handling until patches are applied
• Monitor for memory corruption indicators in application logs