CVE-2009-1379 in OpenSSL
Summary
by MITRE
Use-after-free vulnerability in the dtls1_retrieve_buffered_fragment function in ssl/d1_both.c in OpenSSL 1.0.0 Beta 2 allows remote attackers to cause a denial of service (openssl s_client crash) and possibly have unspecified other impact via a DTLS packet, as demonstrated by a packet from a server that uses a crafted server certificate.
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Analysis
by VulDB Data Team • 12/29/2024
The vulnerability identified as CVE-2009-1379 represents a critical use-after-free flaw within the OpenSSL implementation that specifically affects the dtls1_retrieve_buffered_fragment function located in ssl/d1_both.c. This issue manifests in OpenSSL version 1.0.0 Beta 2 and demonstrates how improper memory management can lead to severe operational consequences. The vulnerability operates within the Datagram Transport Layer Security protocol implementation, which is designed to provide secure communication over unreliable networks through the use of UDP protocols. The flaw occurs when the system processes DTLS packets containing specially crafted server certificates, creating conditions where freed memory locations are accessed after they have been deallocated, leading to unpredictable behavior.
The technical exploitation of this vulnerability occurs through the manipulation of DTLS packet sequences during the handshake process, particularly when the dtls1_retrieve_buffered_fragment function attempts to access memory that has already been freed during previous operations. This use-after-free condition creates a scenario where attackers can craft malicious DTLS packets that trigger memory corruption when processed by the OpenSSL library. The function's failure to properly validate memory references after deallocation creates an opportunity for attackers to either cause the openssl s_client application to crash or potentially execute arbitrary code depending on the specific memory layout and conditions. This type of vulnerability is classified under CWE-416 as Use After Free, which represents a common and dangerous class of memory safety issues that frequently leads to denial of service conditions or more severe security breaches.
The operational impact of CVE-2009-1379 extends beyond simple service disruption as it affects the fundamental reliability and security of DTLS implementations that rely on OpenSSL. When exploited, the vulnerability can cause the openssl s_client tool to crash, effectively preventing legitimate users from establishing secure connections through DTLS protocols. The potential for unspecified other impacts suggests that in certain environments or under specific conditions, attackers might be able to leverage this memory corruption for more advanced exploitation techniques. This vulnerability particularly affects systems that implement DTLS functionality, including but not limited to VPN services, secure messaging applications, and any network infrastructure that relies on OpenSSL for secure communications. The attack vector requires remote execution capability, meaning that an attacker positioned outside the network can potentially exploit this vulnerability without requiring local access or authentication.
Mitigation strategies for this vulnerability involve immediate patching of affected OpenSSL installations to versions that contain the necessary memory management fixes. Organizations should prioritize updating their OpenSSL implementations to versions that address the specific use-after-free condition in the dtls1_retrieve_buffered_fragment function. Additionally, network administrators should consider implementing monitoring solutions that can detect unusual DTLS packet patterns that might indicate exploitation attempts. The ATT&CK framework categorizes this vulnerability under the T1499 category for Network Denial of Service, as the primary impact involves disruption of network services through memory corruption. Security teams should also consider implementing network segmentation and access controls to limit the potential impact of successful exploitation attempts, while maintaining comprehensive logging of DTLS handshake activities to detect anomalous behavior patterns that might indicate active exploitation of this vulnerability.