Description

OP-TEE OS through 4.10.0, fixed in commit 8794043, contains a use-after-free vulnerability in the Trusted Application loader that allows attackers with the ability to load a signed Trusted Application to corrupt secure-world kernel memory by setting the TA_FLAG_CONCURRENT flag in a user TA signed header. Attackers can cause two concurrent sessions to operate on the same shared context without locking, corrupting the uctx->vm_info.regions list during memref parameter mapping and unmapping to free vm_region nodes still in use, resulting in a use-after-free in S-EL1 secure-world kernel memory.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.7",
  "pubDate": "2026-08-10T19:17:32.263Z",
  "pubdate": "2026-08-10T19:17:32.263Z",
  "executiveSummary": "A use-after-free vulnerability exists in the Trusted Application loader of OP-TEE OS through 4.10.0, allowing attackers to corrupt secure-world kernel memory. The flaw affects OP-TEE OS systems running versions up to 4.10.0 where attackers have the capability to load a signed Trusted Application. The primary risk implication is the potential for arbitrary memory corruption and code execution within the S-EL1 secure-world kernel context. Exploitation requires the attacker to possess the ability to load a signed Trusted Application and configure the TA_FLAG_CONCURRENT flag within the user TA signed header. This vulnerability exposes the Trusted Execution Environment to severe privilege escalation and integrity compromises from malicious or manipulated Trusted Applications.",
  "technicalDetails": "The vulnerability resides in the Trusted Application loader component of OP-TEE OS through 4.10.0. The root cause is a lack of proper synchronization and locking mechanisms when handling concurrent sessions for user Trusted Applications that specify the TA_FLAG_CONCURRENT flag in their signed header. Attackers exploit this by initiating two concurrent sessions that operate on the same shared context without adequate locking primitives. During the execution flow, this race condition leads to the corruption of the uctx->vm_info.regions list during the mapping and unmapping of memref parameters. As a result of this list corruption, vm_region nodes that are still actively in use are prematurely freed. Subsequent operations on these prematurely freed nodes trigger a use-after-free condition in S-EL1 secure-world kernel memory. The attack flow involves crafting a user Trusted Application with the TA_FLAG_CONCURRENT flag enabled, loading the signed binary into the OP-TEE environment, and establishing simultaneous concurrent sessions to induce the race condition during parameter mapping and unmapping phases. Post-exploitation impact includes corruption of secure-world kernel memory structures, potentially undermining the security guarantees provided by the Trusted Execution Environment."
}