CVE-2014-3506 in OpenSSL
Summary
by MITRE
d1_both.c in the DTLS implementation in OpenSSL 0.9.8 before 0.9.8zb, 1.0.0 before 1.0.0n, and 1.0.1 before 1.0.1i allows remote attackers to cause a denial of service (memory consumption) via crafted DTLS handshake messages that trigger memory allocations corresponding to large length values.
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Analysis
by VulDB Data Team • 02/10/2022
The vulnerability identified as CVE-2014-3506 represents a critical denial of service flaw within the Datagram Transport Layer Security implementation of OpenSSL. This issue affects multiple versions of the OpenSSL library including 0.9.8 before 0.9.8zb, 1.0.0 before 1.0.0n, and 1.0.1 before 1.0.1i, making it a widespread concern across various security infrastructure components. The flaw resides in the d1_both.c file which handles the DTLS handshake process, specifically during the parsing of handshake messages that contain malformed length fields.
The technical exploitation of this vulnerability occurs when remote attackers craft specially designed DTLS handshake messages containing large length values that trigger excessive memory allocation behaviors within the OpenSSL implementation. This flaw operates at the protocol level where the DTLS implementation fails to properly validate length fields in handshake messages before allocating memory resources. The vulnerability stems from inadequate input validation mechanisms that allow malicious actors to specify arbitrary large values for length parameters, causing the system to allocate excessive memory buffers that can quickly exhaust available system resources.
From an operational impact perspective, this vulnerability creates significant risk for systems relying on OpenSSL for secure communications over unreliable networks. The memory consumption attack can be executed remotely without authentication, making it particularly dangerous for services that handle numerous concurrent connections or operate in resource-constrained environments. The denial of service effect manifests as gradual memory exhaustion that can lead to system instability, application crashes, or complete service unavailability, potentially affecting critical infrastructure components such as web servers, database servers, or network security appliances that utilize OpenSSL for DTLS functionality.
The vulnerability maps directly to CWE-122, which describes "Heap-based Buffer Overflow" and aligns with ATT&CK technique T1499.1, "Network Denial of Service" under the broader category of disruption attacks. Organizations utilizing affected OpenSSL versions face substantial risk of operational disruption, particularly in environments where DTLS is actively used for secure communications. The attack vector requires only network access to the vulnerable service, making it easily exploitable by threat actors without requiring specialized privileges or access to the target system.
Mitigation strategies for CVE-2014-3506 primarily involve immediate patching of affected OpenSSL installations to the latest secure versions. System administrators should prioritize updating all OpenSSL components to versions that include the fix for this vulnerability, which typically involves upgrading to OpenSSL 0.9.8zb, 1.0.0n, or 1.0.1i respectively. Additional protective measures include implementing network-level monitoring to detect unusual memory consumption patterns, configuring rate limiting on DTLS connections, and deploying intrusion detection systems that can identify malformed handshake messages. Organizations should also consider implementing connection pooling and memory allocation limits to reduce the impact if exploitation occurs. The fix typically involves adding proper validation checks for length fields in DTLS handshake message processing, ensuring that memory allocations are bounded by reasonable limits and that malformed length values are rejected before any allocation occurs.