CVE-2024-53106

What it actually does

Out-of-bounds array access in ima_eventdigest_init_common when HASH_ALGO__LAST is passed, causing buffer overrun on hash_digest_size[].

Why it matters to the business

Linux systems relying on IMA for integrity measurement face risk of kernel memory corruption, crashes, or potential privilege escalation; high ecosystem prevalence in servers and embedded devices increases exposure across fleets.

How an attack unfolds

An attacker with local access or the ability to influence IMA measurement events supplies conditions that invoke ima_eventdigest_init with the invalid last hash algorithm constant, triggering the overrun during digest initialization; listed threat actors in 2024 zero-day and Linux kernel campaigns could chain this with other kernel flaws for escalation.

How to fix it

Upgrade Linux kernel to commit e01aae58e818503f2ffcd34c6f7dc6f90af1057e or later; apply Ubuntu package fixes such as botan1.10 1.10.5-1+deb7u1ubuntu0.14.04.1 or 1.10.12-1 where applicable; rebuild and reboot affected systems promptly given the 679 days since publication.

How to confirm the fix worked

Verify kernel source contains the conditional check before array access or confirm running version includes the referenced commit; test IMA measurement paths to ensure no crash on boundary algorithm values.

Typical attack path

1. Gain local execution context on target Linux system
2. Trigger IMA event that reaches ima_eventdigest_init with HASH_ALGO__LAST
3. Cause buffer overrun during array access in ima_eventdigest_init_common
4. Leverage resulting memory corruption for denial of service or code execution

How to detect it

Review kernel logs for IMA-related crashes or oops messages around hash algorithm handling; correlate with process execution of tools that interact with IMA measurement; examine threat actor TTPs from listed espionage and financially motivated campaigns for similar kernel access patterns.

What your security team should do

• Prioritize kernel updates on all IMA-enabled production systems within 48 hours
• Scan for and isolate any unpatched systems using automated configuration management
• Monitor EPSS trend stability and threat actor reports for changes in exploit maturity
• Review downstream dependents and plan staged rollouts to minimize operational disruption