CVE-2012-4523 in radsecproxy
Summary
by MITRE
radsecproxy before 1.6.1 does not properly verify certificates when there are configuration blocks with CA settings that are unrelated to the block being used for verifying the certificate chain, which might allow remote attackers to bypass intended access restrictions and spoof clients.
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Analysis
by VulDB Data Team • 12/20/2021
The vulnerability identified as CVE-2012-4523 affects radsecproxy versions prior to 1.6.1 and represents a critical certificate verification flaw that undermines the security of remote authentication systems. This issue manifests when the software processes configuration blocks containing Certificate Authority settings that are not directly associated with the specific block being used for certificate chain validation. The flaw creates a dangerous scenario where attackers can exploit misconfigured certificate verification logic to bypass intended access controls and impersonate legitimate clients within the network infrastructure.
The technical root cause of this vulnerability lies in the improper certificate chain validation mechanism within radsecproxy's configuration processing. When multiple configuration blocks exist with different CA settings, the software fails to ensure that the certificate verification process uses only the CA parameters relevant to the specific block being validated. This cross-contamination of CA configurations allows malicious actors to present certificates signed by CAs that should not be trusted for the particular verification context, effectively enabling man-in-the-middle attacks against the authentication system.
From an operational perspective, this vulnerability poses significant risks to network security infrastructure that relies on radsecproxy for remote authentication services. The ability to bypass access restrictions means that unauthorized users could gain legitimate access to protected network resources, potentially leading to data breaches, privilege escalation, and complete compromise of the authentication system. Attackers exploiting this flaw could impersonate authorized clients and gain access to sensitive network services, making it particularly dangerous in environments where strong authentication is critical for security.
The vulnerability aligns with CWE-295, which addresses improper certificate validation, and represents a specific instance of improper certificate chain validation that could be classified under the ATT&CK technique T1556.200 for Credential Access - Phishing for Information. Organizations using radsecproxy should immediately implement the patch available in version 1.6.1 and conduct thorough audits of their certificate configuration to ensure that CA settings are properly isolated for each verification context. Additional mitigations include implementing strict certificate validation policies, monitoring for unauthorized certificate usage, and considering alternative authentication methods that do not rely on potentially vulnerable certificate verification mechanisms. The flaw demonstrates the critical importance of proper configuration management and certificate validation in security-critical network services, highlighting how seemingly minor configuration issues can result in major security compromises.