5.7 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
5.3 Medium
AI Score
Confidence
High
0.0004 Low
EPSS
Percentile
10.1%
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.
CPE | Name | Operator | Version |
---|---|---|---|
kernelsu:kernelsu | kernelsu | lt | 0.7.0 |
[
{
"vendor": "tiann",
"product": "KernelSU",
"versions": [
{
"version": ">= 0.6.1, < 0.7.0",
"status": "affected"
}
]
}
]
aospxref.com/android-14.0.0_r2/xref/frameworks/base/core/java/android/util/apk/ApkSigningBlockUtils.java#770
aospxref.com/android-14.0.0_r2/xref/frameworks/base/core/java/android/util/apk/ApkSigningBlockUtils.java#783
drive.google.com/drive/folders/1XdYCCAhC_mkt1k1IyUiwcgFsuOFvwNRl
github.com/tiann/KernelSU/blob/344c08bb79ba12b692016750cda363f9f3500182/kernel/apk_sign.c#L179C32-L179C32
github.com/tiann/KernelSU/blob/344c08bb79ba12b692016750cda363f9f3500182/kernel/apk_sign.c#L188
github.com/tiann/KernelSU/commit/d24813b2c3738f2f9bd762932141cadd948c354f
github.com/tiann/KernelSU/security/advisories/GHSA-86cp-3prf-pwqq
5.7 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
5.3 Medium
AI Score
Confidence
High
0.0004 Low
EPSS
Percentile
10.1%