CVE-2023-1993 in Wireshark
Summary
by MITRE • 04/13/2023
LISP dissector large loop in Wireshark 4.0.0 to 4.0.4 and 3.6.0 to 3.6.12 allows denial of service via packet injection or crafted capture file
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 05/07/2026
The vulnerability identified as CVE-2023-1993 represents a critical denial of service flaw within Wireshark's LISP dissector functionality. This issue affects specific versions of Wireshark including releases from 4.0.0 through 4.0.4 and 3.6.0 through 3.6.12, creating a significant risk for network security analysts and forensic investigators who rely on this packet analysis tool. The vulnerability manifests through a large loop condition that can be triggered by either packet injection attacks or the careful crafting of capture files, potentially causing the application to consume excessive system resources or enter an infinite loop state.
The technical nature of this flaw resides in the LISP (Locator Identification Separation Protocol) dissector implementation within Wireshark's protocol analysis framework. When processing LISP packets or malformed capture files containing LISP data, the dissector encounters a condition that results in an infinite loop during packet parsing. This loop occurs due to improper handling of certain packet structures or field values that cause the dissector to repeatedly process the same data segment without proper termination conditions. The vulnerability specifically targets the dissector's internal loop mechanisms that are designed to parse LISP packet headers and nested structures, where malformed input causes the parsing logic to fail to advance through the packet data correctly.
The operational impact of CVE-2023-1993 extends beyond simple application instability, potentially enabling attackers to perform remote denial of service attacks against systems running vulnerable Wireshark versions. Network security professionals and incident responders who use Wireshark for network forensics, packet analysis, or intrusion detection may find their analysis tools become unresponsive or consume excessive CPU resources when processing maliciously crafted capture files or network traffic containing crafted LISP packets. This vulnerability particularly affects environments where Wireshark is used in automated analysis workflows or where analysts routinely process unknown or untrusted network captures, as the tool may become unavailable during critical investigations. The risk is compounded by the fact that LISP protocol support is often enabled by default in modern Wireshark installations, increasing the attack surface without requiring specific user interaction beyond normal packet analysis activities.
Mitigation strategies for CVE-2023-1993 should prioritize immediate software updates to versions that have patched the LISP dissector loop condition. Users should upgrade to Wireshark versions that contain the specific fix for this vulnerability, typically found in releases following 3.6.13 and 4.0.5. Network security teams should implement defensive measures such as monitoring for unusual CPU usage patterns in analysis environments and establishing procedures to validate capture files before processing potentially untrusted data. Organizations should also consider implementing network segmentation or access controls to limit exposure to crafted packet traffic that could trigger the vulnerable code paths. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1499.001 for resource exhaustion attacks and CWE-835 for infinite loops, representing a classic example of how protocol parsing flaws can be exploited to cause system instability and denial of service conditions. The vulnerability demonstrates the importance of proper input validation and loop termination conditions in network protocol analyzers, where malformed data processing can lead to complete application failure rather than graceful error handling.