Strix
26.1K

CVE-2023-46139

MEDIUMCVSS 5.7/10EPSS 0.17%

Last modified

CVE-2023-46139 is a medium-severity vulnerability rated 5.7/10 on the CVSS scale. 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. EPSS estimates a 0.17% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
5.7/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L

EPSS Probability
0.17%

7.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
KernelsuKernelsu>= 0.6.1, < 0.7.0

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2023-46139?
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.
How severe is CVE-2023-46139?
CVE-2023-46139 has a CVSS score of 5.7/10 (MEDIUM severity). The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.
How do I fix CVE-2023-46139?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2023

View all 2023CVEs →

Are you affected by CVE-2023-46139?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST