# CVE-2023-46139: KernelSU signature validation mismatch

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

- **Severity:** Medium 5.0 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:L`)
- **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 available:** No
- **Published:** 30 Oct 2023
- **Updated:** 5 Sep 2024
- **Also known as:** GHSA-86cp-3prf-pwqq

## 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 (Incorrect Authorization)

## Which versions are affected by CVE-2023-46139?

It affects 1 product.


Products: 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.

## Is CVE-2023-46139 being exploited?

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

## Other vulnerabilities in tiann KernelSU

- [CVE-2023-5521](https://insights.sbomify.com/CVE-2023-5521/): Incorrect Authorization in tiann/kernelsu (high 7.3)
- [CVE-2023-49794](https://insights.sbomify.com/CVE-2023-49794/): The logic of get apk path in KernelSU module can be bypassed (medium 6.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-46139 and fix it if it is affected.

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

Affected product: tiann KernelSU. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-46139/ (Markdown: https://insights.sbomify.com/CVE-2023-46139/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-46139
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-46139
- OSV: https://osv.dev/vulnerability/CVE-2023-46139

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-46139/
Summaries are generated and may contain mistakes; the official description above is the record.