CVE-2015-8012 in lldpd
Summary
by MITRE
lldpd before 0.8.0 allows remote attackers to cause a denial of service (assertion failure and daemon crash) via a malformed packet.
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Analysis
by VulDB Data Team • 04/22/2023
The vulnerability identified as CVE-2015-8012 affects the lldpd daemon version 0.8.0 and earlier, representing a critical denial of service weakness that can be exploited by remote attackers. This issue stems from inadequate input validation within the daemon's packet processing mechanism, specifically when handling malformed network packets. The lldpd service operates as a Link Layer Discovery Protocol daemon, responsible for advertising network device information to neighboring systems and receiving similar information from other devices. When a remote attacker crafts and transmits a malformed packet to a vulnerable lldpd instance, the daemon fails to properly handle the unexpected input structure, leading to an assertion failure that ultimately causes the daemon to crash and restart.
The technical flaw manifests in the daemon's failure to validate packet headers and payload structures before processing them. According to CWE-129, this vulnerability represents an input validation issue where the system does not properly check the boundaries and structure of incoming data. The assertion failure occurs during the packet parsing routine when the daemon encounters unexpected field values or malformed data structures that violate internal assumptions about packet format. This type of vulnerability falls under the ATT&CK technique T1499.004, specifically targeting network denial of service conditions through manipulation of network protocols and services. The daemon's crash results in complete service unavailability, disrupting network discovery mechanisms and potentially affecting network management systems that rely on LLDP information for device inventory and topology mapping.
The operational impact of CVE-2015-8012 extends beyond simple service disruption, as it can compromise network stability and monitoring capabilities. When the lldpd daemon crashes, network administrators lose visibility into connected devices, potentially causing issues with network troubleshooting, asset management, and security monitoring systems that depend on LLDP data. The vulnerability affects any system running vulnerable versions of lldpd, including enterprise network switches, routers, and servers that implement LLDP functionality. The remote exploitation aspect means that attackers do not need physical access or network credentials to trigger the vulnerability, making it particularly dangerous in unsecured network environments where LLDP traffic may traverse untrusted segments. This vulnerability can be leveraged as part of broader network reconnaissance activities or as a component in more sophisticated attack campaigns targeting network infrastructure reliability.
Mitigation strategies for CVE-2015-8012 focus primarily on upgrading to lldpd version 0.8.0 or later, where the input validation has been strengthened to prevent malformed packet processing. System administrators should implement network segmentation and access controls to limit exposure of vulnerable lldpd instances to untrusted networks. Additional protective measures include deploying network monitoring tools that can detect unusual packet patterns and implementing intrusion detection systems that can alert on potential exploitation attempts. The fix implemented in version 0.8.0 addresses the core validation issues by adding proper boundary checks and error handling for packet structures, preventing the assertion failures that previously caused daemon crashes. Organizations should also consider disabling LLDP functionality on network segments where it is not required, reducing the attack surface for this type of vulnerability. Compliance with security standards such as NIST SP 800-53 and ISO 27001 requires implementing such patches and monitoring procedures to maintain network infrastructure resilience against known vulnerabilities.