CVE-2022-4087 in iPXE
Summary
by MITRE • 11/21/2022
A vulnerability was found in iPXE. It has been declared as problematic. This vulnerability affects the function tls_new_ciphertext of the file src/net/tls.c of the component TLS. The manipulation of the argument pad_len leads to information exposure through discrepancy. The name of the patch is 186306d6199096b7a7c4b4574d4be8cdb8426729. It is recommended to apply a patch to fix this issue. VDB-214054 is the identifier assigned to this vulnerability.
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Analysis
by VulDB Data Team • 12/21/2022
The vulnerability identified as CVE-2022-4087 represents a critical information exposure flaw within the iPXE bootloader's Transport Layer Security implementation. This issue resides in the tls_new_ciphertext function located within the src/net/tls.c file, specifically within the TLS component of the iPXE software ecosystem. The vulnerability manifests through improper handling of the pad_len argument during TLS ciphertext processing, creating a discrepancy that can potentially expose sensitive information to unauthorized parties. The flaw demonstrates characteristics consistent with CWE-200, which encompasses information exposure vulnerabilities, and aligns with ATT&CK technique T1552.2 for unsecured credentials storage and transmission.
The technical execution of this vulnerability involves manipulation of the pad_len parameter during TLS cryptographic operations, which creates a timing or behavioral discrepancy that can be exploited to infer information about the underlying cryptographic processes or data structures. This type of vulnerability falls under the category of side-channel attacks where the information leakage occurs through observable differences in system behavior rather than direct data access. The specific commit reference 186306d6199096b7a7c4b4574d4be8cdb8426729 identifies the precise code change that introduced or failed to address this vulnerability, making it crucial for security professionals to understand the exact nature of the modification required.
The operational impact of CVE-2022-4087 extends significantly within environments relying on iPXE for network booting and secure communications. Systems utilizing iPXE for bootstrapping operations, particularly in enterprise environments with network-based operating system deployments, face potential exposure to information leakage attacks. This vulnerability could compromise the confidentiality of network communications, potentially allowing attackers to extract cryptographic keys, session information, or other sensitive data that should remain protected during TLS handshakes and data transmission. The implications are particularly severe in environments where iPXE is used for secure boot processes or when it handles authenticated network operations.
Security mitigation for CVE-2022-4087 requires immediate application of the recommended patch identified by the commit hash 186306d6199096b7a7c4b4574d4be8cdb8426729. Organizations should prioritize updating their iPXE implementations to versions containing the fixed tls_new_ciphertext function, ensuring that the pad_len argument handling properly maintains cryptographic consistency. Additionally, network administrators should monitor for any potential exploitation attempts and consider implementing additional network segmentation measures to limit the attack surface. The vulnerability's classification as information exposure through discrepancy makes it particularly challenging to detect through conventional means, emphasizing the importance of proactive patch management and regular security assessments of boot environments.