CVE-2021-44847 in toxcore
Summary
by MITRE • 12/13/2021
A stack-based buffer overflow in handle_request function in DHT.c in toxcore 0.1.9 through 0.1.11 and 0.2.0 through 0.2.12 (caused by an improper length calculation during the handling of received network packets) allows remote attackers to crash the process or potentially execute arbitrary code via a network packet.
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Analysis
by VulDB Data Team • 12/15/2021
The vulnerability CVE-2021-44847 represents a critical stack-based buffer overflow within the DHT.c component of toxcore software versions 0.1.9 through 0.1.11 and 0.2.0 through 0.2.12. This flaw exists in the handle_request function where improper length calculation during network packet processing creates conditions for malicious input to overflow stack memory boundaries. The affected software serves as the core networking library for the Tox peer-to-peer communication protocol, which is utilized by various decentralized messaging applications and services. The vulnerability stems from inadequate input validation and memory management practices that fail to properly account for packet size constraints during the processing of distributed hash table requests.
The technical implementation of this vulnerability occurs when the handle_request function processes incoming network packets without sufficient bounds checking on the received data length. Specifically, the improper length calculation allows an attacker to craft malicious packets that exceed the allocated stack buffer space, leading to memory corruption that can result in program termination or arbitrary code execution. This type of flaw falls under CWE-121 Stack-based Buffer Overflow, which is classified as a fundamental memory safety issue that has been consistently identified as a primary attack vector in cybersecurity incidents. The vulnerability is particularly concerning because it operates at the network protocol level where attackers can remotely exploit the flaw without requiring local access or authentication.
From an operational perspective, this vulnerability poses significant risks to systems utilizing toxcore libraries, particularly those deployed in networked environments where peer-to-peer communication is enabled. The remote code execution capability means that attackers can potentially gain control over affected systems, leading to data compromise, service disruption, or further lateral movement within network infrastructures. The impact extends beyond individual applications to entire ecosystems that depend on Tox protocol implementations, including messaging platforms, decentralized applications, and communication services. According to ATT&CK framework, this vulnerability maps to T1203 Exploitation for Client Execution and T1059 Command and Scripting Interpreter, representing attack vectors that leverage remote code execution capabilities through network-based exploitation.
Mitigation strategies for CVE-2021-44847 require immediate software updates to versions that address the buffer overflow conditions in the DHT.c file. Organizations should implement network segmentation and monitoring to detect anomalous packet patterns that may indicate exploitation attempts. Input validation measures including strict packet size limits and comprehensive bounds checking should be implemented as defensive programming practices. Security teams should consider deploying intrusion detection systems that can identify malformed network traffic patterns associated with this vulnerability. Additionally, the affected systems should be configured with stack protection mechanisms such as stack canaries and address space layout randomization to reduce exploit reliability. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of vulnerable software versions within the organization's infrastructure, ensuring comprehensive protection against similar memory safety issues that could compromise system integrity and confidentiality.