CVE-2025-48637 Overview
CVE-2025-48637 is a high-severity integer overflow vulnerability in multiple functions of mem_protect.c within the Android kernel. The flaw triggers an out-of-bounds write when arithmetic operations exceed integer boundaries during memory protection routines. A local attacker with low privileges can exploit this condition to escalate privileges on affected Android devices. No user interaction is required for successful exploitation, which lowers the barrier for attack chaining with other local vectors. Google addressed the issue in the December 2025 Android Security Bulletin. The vulnerability is tracked under CWE-190: Integer Overflow or Wraparound.
Critical Impact
An out-of-bounds write in kernel-resident memory protection code enables local privilege escalation to kernel context without user interaction.
Affected Products
- Google Android (kernel component mem_protect.c)
- Devices running Android builds prior to the 2025-12-01 security patch level
- Android Common Kernel branches referenced in Google's upstream fix commits
Discovery Timeline
- 2025-12-01 - Google publishes fix in the Android Security Bulletin
- 2025-12-08 - CVE-2025-48637 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-48637
Vulnerability Analysis
The vulnerability resides in mem_protect.c, a source file used in Android's kernel memory protection paths. Multiple functions perform arithmetic on size or offset values without adequately validating the result against integer boundaries. When the computed value wraps, subsequent memory operations reference regions outside the intended allocation. The out-of-bounds write that follows corrupts adjacent kernel structures.
Because the affected code runs at kernel privilege, an attacker who influences the overflow can steer the write to structures that control execution flow or access rights. The result is local escalation of privilege from an unprivileged app context to kernel-level access. Exploitation requires no additional execution privileges and no user interaction.
Root Cause
The root cause is insufficient bounds checking on arithmetic inputs used to size or offset memory operations. When operands are attacker-influenced, the result overflows the underlying integer type and produces a smaller value than expected. Subsequent buffer or region calculations trust this wrapped value, allowing writes past the intended boundary [CWE-190].
Attack Vector
The attack vector is local. A malicious application or a compromised local process invokes the vulnerable code paths with crafted arguments that trigger the overflow. Because no user interaction is needed, the primitive is usable inside sandboxed app contexts and can be chained with a remote initial-access bug to achieve full device compromise.
No public proof-of-concept exploit has been published. Technical details of the fix are available in the upstream commits 4cfc9c2d8815 and aff2255dbe38.
Detection Methods for CVE-2025-48637
Indicators of Compromise
- Unexpected kernel oops or panic entries in dmesg referencing mem_protect functions or memory protection faults.
- Processes gaining capabilities or UID transitions inconsistent with their normal execution profile.
- Installation of untrusted APKs from sideloaded sources shortly before anomalous kernel events.
Detection Strategies
- Enforce mobile device management policies that verify the Android security patch level is 2025-12-01 or later, and flag devices reporting an earlier build.
- Monitor Android telemetry for kernel crash signatures involving memory protection routines and correlate with the responsible process.
- Inspect installed applications for behavior patterns consistent with local privilege escalation attempts, such as repeated syscall failures preceding a crash.
Monitoring Recommendations
- Aggregate mobile crash and audit logs into a centralized SIEM or data lake for behavioral analysis across the fleet.
- Track patch level compliance continuously rather than at enrollment only, and alert on regressions.
- Watch for post-exploitation behaviors on managed devices, including unauthorized app installs, persistence attempts, and abnormal network egress.
How to Mitigate CVE-2025-48637
Immediate Actions Required
- Apply the December 2025 Android security patch (patch level 2025-12-01 or later) as delivered by the device OEM.
- Prioritize deployment on devices holding sensitive data or accessing corporate resources.
- Restrict installation of applications from untrusted sources and enforce Play Protect on managed devices.
Patch Information
Google released fixes in the Android Security Bulletin dated 2025-12-01. The upstream kernel fixes are published as commits 4cfc9c2d8815 and aff2255dbe38. OEM rollout timing varies; consult your device vendor's advisories for build availability.
Workarounds
- No vendor-provided workaround exists; patching is the only supported remediation.
- Reduce local attack surface by removing unnecessary third-party applications and disabling sideloading via MDM policy.
- Segment devices that cannot be updated from sensitive network resources until they receive the patch.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
