CVE-2018-3620

What it actually does

Allows a local attacker with user access to leak sensitive data from the L1 data cache through terminal page faults combined with side-channel analysis on affected microprocessors using speculative execution.

Why it matters to the business

Potential exposure of confidential information such as credentials or application data on systems running the affected software; impacts 98 downstream dependents and requires prompt patching to avoid operational and compliance risks.

How an attack unfolds

An attacker with local access crafts a sequence of page faults to induce speculative execution that leaves L1 cache residues, then uses timing or cache side-channel techniques to reconstruct the leaked data. No active exploitation by known threat actors has been observed despite the vulnerability's age.

How to fix it

Update tensorflow (Bitnami) to version 2.3.4 or later. Apply available microcode and operating system patches for L1 Terminal Fault on underlying hardware. Disable hyper-threading where performance impact is acceptable and enforce least-privilege local access controls.

How to confirm the fix worked

Confirm tensorflow (Bitnami) reports version 2.3.4 or newer. Verify CPU microcode updates are installed and test that known L1TF proof-of-concept code no longer succeeds on the patched systems.

Typical attack path

1. Obtain local user access on a vulnerable system
2. Trigger repeated terminal page faults to influence speculative execution paths
3. Perform cache side-channel measurements to extract L1 data cache contents
4. Analyze leaked residues to recover sensitive information such as keys or process memory

How to detect it

Review authentication and process creation logs for unexpected local sessions; look for high volumes of page-fault events correlated with cache-timing measurements. No public exploit artifacts are known, so focus on post-exploitation indicators of data exfiltration from affected processes.

What your security team should do

• Immediately upgrade all tensorflow (Bitnami) installations to the fixed version 2.3.4
• Inventory systems for affected hardware and schedule microcode and OS updates
• Reduce local user attack surface and monitor for anomalous page-fault patterns
• Reassess risk after EPSS remains low and no KEV listing appears