CVE-2022-28665 in FreshTomato
Summary
by MITRE • 08/06/2022
A memory corruption vulnerability exists in the httpd unescape functionality of FreshTomato 2022.1. A specially-crafted HTTP request can lead to memory corruption. An attacker can send a network request to trigger this vulnerability.The `freshtomato-arm` has a vulnerable URL-decoding feature that can lead to memory corruption.
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Analysis
by VulDB Data Team • 08/31/2022
The vulnerability identified as CVE-2022-28665 represents a critical memory corruption flaw within the httpd unescape functionality of FreshTomato 2022.1 firmware, specifically affecting the `freshtomato-arm` architecture. This issue arises from improper handling of URL-decoded data within the web server component, creating a pathway for remote code execution through crafted HTTP requests. The vulnerability stems from insufficient bounds checking and memory management during the URL decoding process, which allows attackers to manipulate memory layout and potentially execute arbitrary code with elevated privileges.
The technical implementation of this flaw occurs when the httpd service processes incoming HTTP requests containing specially crafted URL-encoded data. During the unescape operation, the system fails to properly validate input boundaries, leading to buffer overflows or memory corruption patterns that can be exploited to overwrite critical memory segments. This type of vulnerability maps directly to CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The memory corruption manifests when the URL decoding routine processes malformed input sequences that exceed allocated buffer boundaries, potentially causing the web server to crash or behave unpredictably.
From an operational perspective, this vulnerability presents a significant threat to network security as it allows remote attackers to exploit the device without requiring local access or authentication credentials. The attack vector is straightforward - an attacker simply needs to send a crafted HTTP request to the affected device, making this vulnerability particularly dangerous in environments where the device is exposed to untrusted networks. The impact extends beyond mere service disruption as successful exploitation could enable full system compromise, allowing attackers to gain root access to the router and potentially use it as a pivot point for broader network attacks. This aligns with ATT&CK technique T1071.004 for application layer protocol usage and T1059.007 for command and scripting interpreter.
The mitigation strategies for this vulnerability primarily involve updating to the latest firmware version that addresses the memory corruption issue in the URL decoding routine. Network administrators should implement immediate patch management procedures to ensure all affected FreshTomato devices are updated with the patched version. Additionally, network segmentation and firewall rules can be employed to restrict access to the web administration interface, limiting the attack surface. Monitoring for suspicious HTTP requests and implementing intrusion detection systems can help identify exploitation attempts. The vulnerability also highlights the importance of proper input validation and memory management practices in embedded systems, particularly those handling network protocols, as emphasized by security frameworks such as the OWASP Top Ten and NIST SP 800-160 standards for secure software development practices.