CVE-2015-2153 in tcpdump
Summary
by MITRE
The rpki_rtr_pdu_print function in print-rpki-rtr.c in the TCP printer in tcpdump before 4.7.2 allows remote attackers to cause a denial of service (out-of-bounds read or write and crash) via a crafted header length in an RPKI-RTR Protocol Data Unit (PDU).
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 11/21/2024
The vulnerability identified as CVE-2015-2153 represents a critical buffer handling flaw within tcpdump's RPKI-RTR protocol processing functionality. This issue specifically affects the rpki_rtr_pdu_print function located in the print-rpki-rtr.c file, which is part of tcpdump's TCP printer module. The vulnerability manifests when tcpdump processes RPKI-RTR Protocol Data Units, which are used for exchanging Route Origin Authorization information in Internet routing security contexts. The flaw arises from inadequate validation of header length fields within these PDUs, creating an exploitable condition that can be leveraged by remote attackers to disrupt the normal operation of network monitoring tools.
The technical exploitation of this vulnerability occurs through manipulation of the header length field within RPKI-RTR PDUs, which causes the rpki_rtr_pdu_print function to perform out-of-bounds memory reads or writes. This type of flaw falls under the CWE-125 vulnerability category, which encompasses out-of-bounds read conditions, and may also involve CWE-787 for out-of-bounds write operations. When an attacker crafts a malicious PDU with an invalid header length value, the function attempts to process memory locations beyond the allocated buffer boundaries, resulting in unpredictable behavior including application crashes, memory corruption, or potential privilege escalation depending on the execution context. The vulnerability demonstrates characteristics consistent with the attack pattern described in MITRE ATT&CK technique T1499.001 for network denial of service attacks.
The operational impact of CVE-2015-2153 extends beyond simple service disruption to potentially compromise network security monitoring capabilities. Network administrators who rely on tcpdump for traffic analysis and security auditing may find their monitoring tools rendered ineffective when processing malicious RPKI-RTR traffic, creating blind spots in network security infrastructure. This vulnerability particularly affects organizations that implement RPKI-based route validation systems, as these systems depend on proper processing of RPKI-RTR PDUs for maintaining accurate routing information. The denial of service condition can be exploited in various network scenarios including man-in-the-middle attacks where attackers inject malicious PDUs into legitimate RPKI communication channels, or through direct attacks against network monitoring infrastructure that processes RPKI data. The vulnerability affects tcpdump versions prior to 4.7.2, making systems running older versions particularly susceptible to exploitation.
Mitigation strategies for CVE-2015-2153 should prioritize immediate patching of tcpdump installations to version 4.7.2 or later, which contains the necessary fixes for proper header length validation. Organizations should also implement network segmentation and access controls to limit exposure of tcpdump instances to untrusted network traffic, particularly in environments where RPKI-RTR protocol processing is enabled. Additional defensive measures include configuring tcpdump to process RPKI-RTR traffic through restricted network interfaces or implementing traffic filtering rules that can identify and block malformed PDUs before they reach the vulnerable processing functions. Network monitoring systems should also be configured to alert administrators when tcpdump crashes or exhibits abnormal behavior, as these incidents may indicate successful exploitation attempts. The fix implemented in tcpdump 4.7.2 addresses the root cause by adding proper bounds checking and validation of header length fields before any memory operations are performed, preventing the out-of-bounds access conditions that led to the vulnerability.