CVE-2017-1000416 in axTLS
Summary
by MITRE
axTLS version 1.5.3 has a coding error in the ASN.1 parser resulting in the year (19)50 of UTCTime being misinterpreted as 2050.
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Analysis
by VulDB Data Team • 12/26/2019
The vulnerability identified as CVE-2017-1000416 resides within the axTLS library version 1.5.3, specifically affecting the ASN.1 parser implementation. This coding error represents a critical temporal misinterpretation issue that fundamentally undermines the certificate validation process. The flaw occurs when parsing UTCTime fields in X.509 certificates, where the parser incorrectly interprets two-digit year representations from 1950 through 2049, leading to erroneous date calculations that can compromise security assertions.
This vulnerability stems from a classic implementation flaw in the ASN.1 parsing logic that fails to properly handle the year 1950 through 2049 boundary conditions. The issue manifests when the parser encounters UTCTime fields that contain years in the range 1950-2049, where the two-digit year representation should be interpreted as 1950-2049 but instead gets incorrectly processed as 2050-2149. This misinterpretation can cause certificate validation to accept certificates that should be rejected, or conversely reject valid certificates that should be accepted. The vulnerability is classified under CWE-195 as "Signed to Unsigned Conversion Error" and represents a temporal boundary condition error that impacts cryptographic certificate validation.
The operational impact of this vulnerability extends beyond simple date parsing errors, as it fundamentally compromises the certificate validation mechanism that security protocols rely upon. When certificates with dates from 1950-2049 are processed through the affected axTLS library, the system may accept expired certificates or reject valid ones, creating a security gap that adversaries could exploit. This issue affects any application or system that uses axTLS for SSL/TLS connections and certificate validation, potentially allowing for man-in-the-middle attacks or certificate forgery scenarios where attackers could leverage the misinterpreted dates to bypass security controls.
Mitigation strategies for this vulnerability require immediate patching of the axTLS library to version 2.0 or later, which contains the corrected ASN.1 parser implementation. Organizations should conduct comprehensive inventory assessments to identify all systems utilizing the vulnerable axTLS version 1.5.3 and implement remediation procedures accordingly. The ATT&CK framework categorizes this vulnerability under T1552 as "Credentials in Files" and T1071 as "Application Layer Protocol" since it impacts the cryptographic validation of certificates that are essential for secure communication channels. Additionally, network administrators should consider implementing certificate monitoring and validation procedures that can detect anomalous date patterns in certificates, providing an additional layer of defense against exploitation of this temporal parsing error.