CVE-2020-8944 : Exploit Details and Defense Strategies
Learn about CVE-2020-8944, an arbitrary memory write vulnerability in Asylo versions up to 0.6.0, allowing attackers to exploit ecall_restore function. Find mitigation steps and upgrade recommendations.
An arbitrary memory write vulnerability in Asylo versions up to 0.6.0 allows an untrusted attacker to exploit the ecall_restore function, potentially leading to arbitrary memory write operations within the secure enclave.
Understanding CVE-2020-8944
This CVE involves an unchecked buffer overrun in the ecall_restore function of Asylo versions up to 0.6.0, posing a security risk to the system.
What is CVE-2020-8944?
CVE-2020-8944 is a vulnerability in Asylo that enables an attacker to perform arbitrary memory writes by exploiting the ecall_restore function without proper pointer range validation.
The Impact of CVE-2020-8944
The vulnerability has a CVSS base score of 5.3, indicating a medium severity issue with high confidentiality impact and low integrity impact. The attack complexity is high, requiring low privileges and no user interaction.
Technical Details of CVE-2020-8944
This section provides detailed technical information about the vulnerability.
Vulnerability Description
The vulnerability allows an untrusted attacker to call ecall_restore with the 'output' attribute, bypassing pointer range checks and enabling arbitrary memory writes, including within the secure enclave.
Affected Systems and Versions
- Product: Asylo
- Vendor: Google LLC
- Versions Affected: <= 0.6.0 (custom version)
Exploitation Mechanism
The attacker can leverage the ecall_restore function to write to arbitrary memory addresses, potentially compromising the security of the system.
Mitigation and Prevention
Protect your system from CVE-2020-8944 with the following steps:
Immediate Steps to Take
- Upgrade Asylo to a version beyond commit 382da2b8b09cbf928668a2445efb778f76bd9c8a to mitigate the vulnerability.
Long-Term Security Practices
- Regularly update software and libraries to patch known vulnerabilities.
- Implement secure coding practices to prevent buffer overflows and memory corruption.
Patching and Updates
- Apply patches and updates provided by the vendor to address security issues promptly.