CVE-2023-5521Public exploit

Root takeover via weak manager signature validation

Published Oct 11, 2023 · Updated Sep 18, 2024

Incorrect authorization in KernelSU before 0.6.9 allows local users to gain root by installing a malicious Android application. The kernel's APK parser authenticates the Manager certificate by its length and a collision-prone 32-bit hash, allowing a crafted signature to pass. Exploitation requires user interaction to install the crafted APK on a device running the affected kernel; successful spoofing assigns its UID Manager authority over root access.

CVSS severity7.3
High
EPSS probability0.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in KernelSU before 0.6.9 allows local users to gain root by installing a malicious Android application. The kernel's APK parser authenticates the Manager certificate by its length and a collision-prone 32-bit hash, allowing a crafted signature to pass. Exploitation requires user interaction to install the crafted APK on a device running the affected kernel; successful spoofing assigns its UID Manager authority over root access.

The record

CVE
CVE-2023-5521
Published
Oct 11, 2023
Updated
Sep 18, 2024
Vendor
tiann
Product
KernelSU
Classifications
CWE-863, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 11, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <0.6.9
  2. Affected versionversion=unspecified <v0.6.9

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

tiann · KernelSUversion=0 <0.6.9; version=unspecified <v0.6.9

Published CVSS scores

7.3huntr.devCVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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