CVE-2017-7702 in Wireshark
Summary
by MITRE
In Wireshark 2.2.0 to 2.2.5 and 2.0.0 to 2.0.11, the WBXML dissector could go into an infinite loop, triggered by packet injection or a malformed capture file. This was addressed in epan/dissectors/packet-wbxml.c by adding length validation.
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Analysis
by VulDB Data Team • 11/29/2022
The vulnerability identified as CVE-2017-7702 represents a critical denial of service flaw within Wireshark's WBXML dissector component. This issue affected versions ranging from 2.2.0 through 2.2.5 and 2.0.0 through 2.0.11, creating a significant risk for network forensics professionals who rely on Wireshark for protocol analysis. The WBXML dissector is responsible for parsing Wireless Binary XML format data, which is commonly encountered in mobile network communications and wireless protocols. The flaw manifested when the dissector encountered malformed packet data or specially crafted capture files that could trigger unexpected behavior in the parsing logic.
The technical root cause of this vulnerability lies in insufficient input validation within the packet-wbxml.c source file. When processing WBXML data, the dissector failed to properly validate the length parameters of the parsed elements, allowing attackers to craft malicious packets that would cause the dissector to enter an infinite loop during processing. This condition occurred because the dissector's loop control mechanisms were not properly bounded by length checks, enabling attackers to manipulate the parsing process through crafted data structures that would cause the loop to continue indefinitely. The vulnerability falls under CWE-835, which specifically addresses infinite loops in software implementations, making it particularly dangerous in network analysis tools where processing time and resource consumption are critical factors.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it could potentially disrupt network analysis operations and compromise the availability of critical forensic data. Network security analysts and incident responders who use Wireshark for packet inspection could find their analysis tools become unresponsive or crash when encountering maliciously crafted capture files. This disruption could occur during live network monitoring, forensic investigations, or automated analysis processes where Wireshark might be processing large volumes of traffic. The vulnerability's exploitation through packet injection means that remote attackers could potentially trigger this condition without requiring local access to the system, making it particularly concerning for network monitoring environments. According to ATT&CK framework tactic TA0005 (Defense Evasion), this vulnerability could be leveraged to evade detection by causing analysis tools to become unresponsive, potentially masking malicious network activity.
The remediation implemented in epan/dissectors/packet-wbxml.c addressed the core issue by adding proper length validation checks to prevent the infinite loop condition. This fix ensures that all WBXML elements are properly bounded before processing, preventing attackers from crafting malformed data that could cause the dissector to enter an endless processing cycle. The solution aligns with defensive programming practices and follows industry standards for input validation that are recommended in both CWE guidelines and secure coding principles. Organizations that rely on Wireshark for network analysis should prioritize updating to patched versions to eliminate this vulnerability and ensure continued operational stability during forensic investigations and network monitoring activities.