CVE-2020-8941 in Asylo
Summary
by MITRE • 12/15/2020
An arbitrary memory read vulnerability in Asylo versions up to 0.6.0 allows an untrusted attacker to make a call to enc_untrusted_inet_pton using an attacker controlled klinux_addr_buffer parameter. The parameter size is unchecked allowing the attacker to read memory locations outside of the intended buffer size including memory addresses within the secure enclave. We recommend upgrading past commit 8fed5e334131abaf9c5e17307642fbf6ce4a57ec
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Analysis
by VulDB Data Team • 12/16/2020
This vulnerability represents a critical memory safety issue in the Asylo secure computing framework that enables unauthorized memory access through improper input validation. The flaw exists in the enc_untrusted_inet_pton function where the klinux_addr_buffer parameter lacks proper size validation, creating an arbitrary memory read condition that can be exploited by untrusted attackers. The vulnerability specifically affects Asylo versions up to 0.6.0 and stems from insufficient bounds checking that allows attackers to manipulate buffer size parameters to access memory locations beyond the intended allocation boundaries.
The technical implementation of this vulnerability leverages the unchecked parameter size to craft malicious inputs that cause the system to read memory addresses within the secure enclave boundaries. This creates a serious confidentiality risk as attackers can potentially extract sensitive information from memory locations that should remain protected within the enclave environment. The flaw operates at the kernel level interface where untrusted inputs are processed, making it particularly dangerous as it can be triggered through normal network protocol handling operations that the framework typically processes.
From an operational perspective this vulnerability poses significant risks to systems relying on Asylo for confidential computing workloads, as it undermines the fundamental security guarantees that secure enclaves are designed to provide. The arbitrary memory read capability could potentially expose cryptographic keys, sensitive data, or system internals that should remain isolated within the secure execution environment. This represents a direct violation of the principle of least privilege and could enable further exploitation techniques such as information leakage that might facilitate more sophisticated attacks against the protected system components.
The recommended mitigation strategy involves upgrading to a version that includes the fix referenced in commit 8fed5e334131abaf9c5e17307642fbf6ce4a57ec, which addresses the unchecked parameter validation issue. Organizations should also implement additional monitoring for anomalous memory access patterns and consider validating all external inputs through proper bounds checking mechanisms. This vulnerability aligns with CWE-129, which addresses improper validation of input ranges, and could potentially be leveraged as part of a broader attack chain that maps to ATT&CK technique T1005 for data from local system storage and T1552 for credentials theft through memory access techniques. The fix should be prioritized in security update cycles to prevent potential exploitation in production environments where Asylo is deployed for confidential computing scenarios.