CVE-2022-25740 in 9205 LTE Modem
Summary
by MITRE • 04/13/2023
Memory corruption in modem due to buffer overwrite while building an IPv6 multicast address based on the MAC address of the iface
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Analysis
by VulDB Data Team • 04/13/2023
This vulnerability represents a critical memory corruption issue within modem firmware that arises from improper buffer handling during IPv6 multicast address construction. The flaw occurs when the modem processes network interface MAC addresses to generate IPv6 multicast addresses, creating a scenario where insufficient bounds checking allows data to overwrite adjacent memory regions. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, though it manifests in a more complex memory corruption pattern typical of embedded systems. The root cause stems from inadequate input validation and memory management practices within the IPv6 address generation routine, where the system fails to properly constrain the size of data being written to memory buffers. The vulnerability specifically impacts modem implementations that handle IPv6 multicast traffic and are configured to use MAC address-based multicast address formation, which is a standard practice in network interface management.
The operational impact of this vulnerability extends beyond simple memory corruption to potentially enable remote code execution within the modem's processing environment. Attackers can exploit this flaw by crafting malicious network traffic that triggers the vulnerable code path during multicast address construction, leading to arbitrary code execution with the privileges of the modem process. This represents a significant threat to network infrastructure security, as modems typically operate with elevated privileges and maintain access to core network functions. The vulnerability's exploitation potential aligns with ATT&CK technique T1059.007 for command and control through modem interfaces, and T1566 for initial access via network-based attacks. The memory corruption can manifest as system crashes, denial of service conditions, or more severe outcomes including persistent backdoor establishment within the device's firmware environment.
Mitigation strategies must address both immediate protection and long-term firmware hardening measures. Immediate actions include implementing proper buffer size validation and bounds checking within the IPv6 multicast address construction code, ensuring that MAC address data is properly truncated or validated before buffer operations. Network administrators should consider disabling IPv6 multicast functionality on affected devices when possible, and implementing network segmentation to limit exposure. Firmware updates from vendors are essential, as these patches typically include memory safety improvements and enhanced input validation routines. The fix should incorporate defensive programming practices such as using safe string handling functions, implementing stack canaries, and employing address space layout randomization where applicable. Additionally, continuous monitoring of modem network traffic for unusual multicast address patterns and implementing intrusion detection systems can help identify exploitation attempts. Organizations should also consider implementing device firmware integrity verification mechanisms and establishing secure update procedures to prevent exploitation during firmware installation phases.