CVE-2023-46139 KernelSU signature validation mismatch

Medium 5.0 Published Updated

Malicious apps can bypass KernelSU signature checks to gain root privileges on Android devices due to inconsistent verification logic.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
A user has to click or open something
Fix
None listed

What is CVE-2023-46139?

CVE-2023-46139 is a medium-severity authentication bypass vulnerability in tiann KernelSU, published on 30 Oct 2023. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

KernelSU is a Kernel based root solution for Android. Starting in version 0.6.1 and prior to version 0.7.0, if a KernelSU installed device is infected with a malware whose app signing block specially constructed, it can take over root privileges on the device. The vulnerable verification logic actually obtains the signature of the last block with an id of `0x7109871a`, while the verification logic during Android installation is to obtain the first one. In addition to the actual signature upgrade that has been fixed (KSU thought it was V2 but was actually V3), there is also the problem of actual signature downgrading (KSU thought it was V2 but was actually V1). Find a condition in the signature verification logic that will cause the signature not to be found error, and KernelSU does not implement the same conditions, so KSU thinks there is a V2 signature, but the APK signature verification actually uses the V1 signature. This issue is fixed in version 0.7.0. As workarounds, keep the KernelSU manager installed and avoid installing unknown apps.

Weakness: CWE-863

Which versions are affected by CVE-2023-46139?

It affects 1 product.

Products include Kernelsu Kernelsu.

How do I fix CVE-2023-46139?

No fix has been published for CVE-2023-46139 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2023-46139 being exploited?

There is no known exploitation of CVE-2023-46139 in the wild and no public exploit code.

Sources

Also known as GHSA-86cp-3prf-pwqq.

Is CVE-2023-46139 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free