CVE-2014-3467 in Libtasn1
Summary
by MITRE
Multiple unspecified vulnerabilities in the DER decoder in GNU Libtasn1 before 3.6, as used in GnuTLS, allow remote attackers to cause a denial of service (out-of-bounds read) via crafted ASN.1 data.
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Analysis
by VulDB Data Team • 06/20/2021
The vulnerability identified as CVE-2014-3467 represents a critical security flaw within the GNU Libtasn1 library version 3.5 and earlier, which serves as a core component in the GnuTLS cryptographic library ecosystem. This issue manifests as multiple unspecified vulnerabilities specifically within the Distinguished Encoding Rules (DER) decoder implementation, creating a significant attack surface that adversaries can exploit to disrupt system operations. The affected library is widely deployed across various operating systems and applications that rely on ASN.1 encoding standards for cryptographic operations, making this vulnerability particularly dangerous in environments where secure communications are paramount.
The technical nature of this vulnerability stems from improper bounds checking within the DER decoder functionality of GNU Libtasn1, which processes ASN.1 encoded data structures using the Distinguished Encoding Rules standard. When encountering crafted malicious ASN.1 data, the decoder fails to properly validate array indices or memory boundaries, resulting in out-of-bounds read conditions. This memory safety issue allows attackers to manipulate the decoder's behavior by supplying specially constructed ASN.1 sequences that trigger memory access violations. The vulnerability specifically affects the parsing of ASN.1 structures that follow the DER encoding format, which is a strict subset of the Basic Encoding Rules (BER) and commonly used in X.509 certificates, TLS handshakes, and other cryptographic protocols.
The operational impact of CVE-2014-3467 extends beyond simple denial of service conditions, as it can potentially lead to system instability and service disruption across applications that depend on GnuTLS for secure communications. When exploited successfully, the out-of-bounds read conditions can cause application crashes, memory corruption, or even allow attackers to infer sensitive information from memory contents through information leakage attacks. This vulnerability affects a broad range of systems including web servers, email servers, VPN implementations, and any software that employs GnuTLS for cryptographic operations, making it a critical concern for system administrators and security professionals managing enterprise infrastructure. The impact is particularly severe in environments where continuous availability is required, as the vulnerability can be triggered through legitimate network traffic without requiring authentication.
Organizations should prioritize immediate patching of all systems running GNU Libtasn1 versions prior to 3.6, as this vulnerability represents a known threat in the cybersecurity landscape and has been documented in various threat intelligence feeds and vulnerability databases. The remediation process involves upgrading to GNU Libtasn1 version 3.6 or later, which includes proper bounds checking and memory validation mechanisms within the DER decoder. System administrators should also implement network monitoring to detect potential exploitation attempts through malformed ASN.1 data patterns, as the vulnerability can be triggered by simple network-based attacks without requiring complex exploitation techniques. Additionally, organizations should conduct comprehensive vulnerability assessments to identify all systems utilizing affected versions of GnuTLS and related cryptographic libraries, ensuring complete remediation across their infrastructure.
This vulnerability aligns with CWE-125 (Out-of-bounds Read) and CWE-787 (Out-of-bounds Write) categories from the Common Weakness Enumeration catalog, demonstrating the fundamental nature of memory safety issues in cryptographic libraries. From an attacker perspective, this vulnerability maps to ATT&CK technique T1203 (Exploitation for Client Execution) and T1499 (Endpoint Denial of Service) within the MITRE ATT&CK framework, as it enables adversaries to disrupt services through crafted data inputs. The vulnerability also reflects broader concerns about software supply chain security, as cryptographic libraries form foundational components of security infrastructure, making the compromise of such libraries particularly damaging to overall system security posture.