CVE-2024-53103

What it actually does

The flaw leaves vsk->trans uninitialized to NULL on hvs release, creating a dangling pointer that can be dereferenced later and trigger a use-after-free condition in the Linux kernel hv_sock code path.

Why it matters to the business

Linux-based systems may experience crashes, memory corruption, or potential privilege escalation that disrupts services, increases incident response costs, and raises the risk of data exposure on servers running the affected kernel versions.

How an attack unfolds

An attacker with local access crafts operations that cause hvs release while vsk->trans still holds a stale pointer; subsequent dereference of that pointer leads to use-after-free, which can be leveraged for memory corruption or code execution. Listed threat actors have been associated with similar Linux kernel uninitialized-resource and out-of-bounds issues in recent campaigns.

How to fix it

Upgrade affected openssl packages on Ubuntu 14.04 LTS to 1.0.1f-1ubuntu2.20 and on Ubuntu 16.04 LTS to 1.0.2g-1ubuntu4.4; apply equivalent kernel updates that initialize vsk->trans to NULL before hvs release.

How to confirm the fix worked

Confirm the running kernel and openssl packages match or exceed the listed fixed versions; inspect hv_sock source for the NULL initialization of vsk->trans and run regression tests that exercise hvs release paths.

Typical attack path

1. Obtain local access or execute code on a target Linux system
2. Trigger hv_sock hvs release without ensuring vsk->trans is set to NULL
3. Force subsequent dereference of the dangling pointer
4. Exploit the resulting use-after-free for memory corruption or privilege escalation

How to detect it

Search kernel logs and crash dumps for hv_sock or vsk trans dereference errors; correlate with process activity around socket release operations; review any alerts tied to the listed threat actor campaigns involving Linux kernel memory issues.

What your security team should do

• Prioritize patching systems that expose hv_sock or run the listed Ubuntu releases within the next 30 days
• Monitor EPSS and KEV updates for any change in exploitation likelihood
• Review logs for hv_sock related crashes or use-after-free signatures