CVE-2018-9539

HIGH

Android 8.0-9 - Use-After-Free via ClearKey CAS Descrambler Race Condition

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2018-9539. PoCs published by tamirzb, codecat007.

AI-analyzed exploit summary This is a proof-of-concept exploit for CVE-2018-9539, a use-after-free vulnerability in Android's ClearKey CAS module. The PoC demonstrates a race condition leading to a crash in Android 9.0 by manipulating descrambler sessions.

Description

In the ClearKey CAS descrambler, there is a possible use after free due to a race condition. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Product: Android. Versions: Android-8.0 Android-8.1 Android-9. Android ID: A-113027383

Exploits (2)

nomisec WORKING POC 20 stars
by tamirzb · poc
https://github.com/tamirzb/CVE-2018-9539

This is a proof-of-concept exploit for CVE-2018-9539, a use-after-free vulnerability in Android's ClearKey CAS module. The PoC demonstrates a race condition leading to a crash in Android 9.0 by manipulating descrambler sessions.

Classification
Working Poc 95%
Attack Type
Dos
Complexity
Complex
Reliability
Racy
Target: Android 8.1-9.0 (before November 2018)
No auth needed
Prerequisites: Android source code · Unpatched Android 8.1-9.0 device
devstral-2 · analyzed Feb 16, 2026 Full analysis →
github WORKING POC 8 stars
by codecat007 · cpoc
https://github.com/codecat007/cvehub/tree/main/android/securityPatch/CVE-2018-9539

This PoC exploits a race condition in Android's ClearKey CAS (Conditional Access System) by manipulating session references during concurrent descramble operations, leading to a use-after-free vulnerability. The exploit uses multiple threads to trigger the race condition, potentially causing a service crash or arbitrary code execution.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Complex
Reliability
Racy
Target: Android ClearKey CAS (Conditional Access System) before security patch
No auth needed
Prerequisites: Access to Android device with vulnerable ClearKey CAS implementation
devstral-2 · analyzed Feb 27, 2026 Full analysis →

References (2)

Core 2
Core References
Third Party Advisory, VDB Entry vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/105865
Patch, Vendor Advisory x_refsource_confirm
https://source.android.com/security/bulletin/2018-11-01

Scores

CVSS v3 7.0
EPSS 0.0017
EPSS Percentile 38.8%
Attack Vector LOCAL
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-362
Status published
Products (3)
google/android 8.0
google/android 8.1
google/android 9.0
Published Nov 14, 2018
Tracked Since Feb 18, 2026