CVE-2018-6953 in CCN-lite
Summary
by MITRE
In CCN-lite 2, the Parser of NDNTLV does not verify whether a certain component's length field matches the actual component length, which has a resultant buffer overflow and out-of-bounds memory accesses.
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Analysis
by VulDB Data Team • 02/06/2023
The vulnerability identified as CVE-2018-6953 affects CCN-lite version 2, a software implementation of the Content Centric Networking (CCN) protocol stack. This issue resides within the NDNTLV (Named Data Networking Transport Level Protocol) parser component that processes incoming network packets. The flaw represents a critical security weakness that can lead to arbitrary code execution and system compromise. The vulnerability is classified under CWE-129 Improper Validation of Array Index, which specifically addresses situations where array indices are not properly validated, leading to buffer overflows and memory corruption. The affected parser fails to perform proper validation checks on the length fields contained within TLV (Type-Length-Value) encoded packets, creating a scenario where malformed data can cause unpredictable behavior in the application's memory management.
The technical implementation of this vulnerability stems from the parser's failure to validate the integrity of the length field in NDNTLV components before using it for memory allocation or access operations. When processing incoming packets, the parser reads the length field from the TLV structure and assumes it represents the actual component length without performing a verification check. This assumption allows an attacker to craft malicious packets with manipulated length values that exceed the actual data boundaries. The parser subsequently allocates memory or accesses memory regions based on these incorrect length values, resulting in out-of-bounds memory accesses that can overwrite adjacent memory locations, corrupt data structures, or potentially execute arbitrary code. This type of vulnerability falls under the ATT&CK technique T1059.007 Command and Scripting Interpreter: Python, as it enables attackers to leverage the parser's memory corruption capabilities to execute malicious payloads through carefully crafted network traffic.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it can enable remote code execution on systems running vulnerable versions of CCN-lite. Attackers can exploit this weakness by sending specially crafted NDNTLV packets to the target system, potentially leading to complete system compromise. The vulnerability affects the integrity and availability of CCN-based networks, as compromised systems can no longer be trusted to properly process or forward content. Organizations relying on CCN-lite for content-centric networking applications face significant risk, particularly in environments where the software serves as a core component of network infrastructure. The memory corruption resulting from this buffer overflow can cause unpredictable behavior, including application crashes, data corruption, or unauthorized access to system resources, making it particularly dangerous in production environments where network reliability and security are paramount.
Mitigation strategies for CVE-2018-6953 should focus on immediate patching of affected CCN-lite installations, with the vendor releasing updated versions that implement proper length validation checks in the NDNTLV parser. Organizations should also implement network monitoring and intrusion detection systems to identify potential exploitation attempts through malformed NDNTLV packets. The recommended approach includes validating all length fields in TLV structures before using them for memory operations, implementing bounds checking mechanisms, and ensuring proper input sanitization. Additionally, network segmentation and access controls should be enforced to limit exposure to potentially malicious traffic, while regular security audits should verify that all components of the CCN infrastructure properly validate data integrity. The vulnerability demonstrates the critical importance of implementing robust input validation in network protocol implementations, as highlighted by ATT&CK technique T1210 Exploitation of Remote Services, which emphasizes the need for proper validation of network inputs to prevent exploitation of memory corruption vulnerabilities.