CVE-2021-0332
About
In bootFinished of SurfaceFlinger.cpp, there is a possible memory corruption due to a use after free. This could lead to local escalation of privilege with User execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11 Android-10Android ID: A-169256435
Rainforest analyst review
A use-after-free in Android's SurfaceFlinger, in the bootFinished path, allows local privilege escalation, and notably no user interaction is required once a malicious app is running. The catch is in that phrasing: the escalation starts from local execution privileges, meaning an attacker-controlled app already on the device.
So the threat model is a malicious or compromised app climbing from its sandbox toward higher privilege, not a remote intrusion. It's an escalation link that a hostile app would use after installation, which is why it needs the app to be present and running first.
We manage this through mobile fleet patch level across the affected Android 10 and 11 builds, and we characterize it accurately as a post-install escalation rather than an entry point. That framing keeps it prioritized against the right risk, sideloaded or malicious apps, rather than as an internet-facing exposure.
References
Related CVEs
Frequently asked questions
What is CVE-2021-0332?
In bootFinished of SurfaceFlinger.cpp, there is a possible memory corruption due to a use after free. This could lead to local escalation of privilege with User execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11 Android-10Android ID: A-169256435
How severe is CVE-2021-0332?
CVE-2021-0332 carries a CVSS 3.1 base score of 7.8, rated high. On the Rainforest Risk Index — which weighs the severity alongside how easy the flaw is to reach and how broad its impact is — it scores 73 out of 100, in the high band.
How is CVE-2021-0332 exploited?
According to the CVSS vector (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H): attack vector Local, attack complexity Low, privileges required Low, user interaction None. Impact on confidentiality High, integrity High and availability High.
Which products are affected by CVE-2021-0332?
Public advisories list the following as affected: android. Check the references on this page for the exact versions each vendor confirms.
How do I fix CVE-2021-0332?
Apply the fix the vendor published — the references on this page link to the primary advisories and patches. When patching can't happen right away, reduce the exposure of the affected component and watch it for exploitation attempts. Rainforest customers see this vulnerability correlated to their own assets and prioritized by real exposure, not by score alone.
Empower Your Security Strategy with Rainforest
Discover vulnerabilities early, prioritize critical threats, and protect what truly matters. Rainforest streamlines your security operations, saving you time and reducing costs, so you can focus on what drives your business forward.