CVE-2021-45525 in EX7000
Summary
by MITRE • 12/26/2021
Certain NETGEAR devices are affected by a buffer overflow by an authenticated user. This affects EX7000 before 1.0.1.80, R6400 before 1.0.1.50, R6400v2 before 1.0.4.118, R6700 before 1.0.2.8, R6700v3 before 1.0.4.118, R6900 before 1.0.2.8, R6900P before 1.3.2.124, R7000 before 1.0.9.88, R7000P before 1.3.2.124, R7900 before 1.0.3.18, R7900P before 1.4.1.50, R8000 before 1.0.4.46, R8000P before 1.4.1.50, RAX80 before 1.0.1.56, and WNR3500Lv2 before 1.2.0.62.
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Analysis
by VulDB Data Team • 12/28/2021
This vulnerability represents a critical buffer overflow flaw in NETGEAR router firmware that can be exploited by authenticated users with access to the device's administrative interface. The issue stems from improper input validation within the web-based management interface of affected devices, creating a condition where maliciously crafted input can overwrite adjacent memory locations in the application's heap. The vulnerability affects a broad range of NETGEAR routers including the EX7000, R6400 series, R6700 series, R6900 series, R7000 series, R7900 series, R8000 series, RAX80, and WNR3500Lv2 models. The affected firmware versions indicate that this is a long-standing issue that was not properly addressed in the device's software lifecycle, leaving numerous network endpoints vulnerable to exploitation.
The technical implementation of this buffer overflow occurs when authenticated users submit specially crafted input to the device's web interface through HTTP POST requests or form submissions. The flaw is categorized under CWE-121 as a stack-based buffer overflow, though it could also manifest as heap-based overflow depending on the specific implementation details. When the application processes user input without proper bounds checking, it allows attackers to overwrite memory structures that control program execution flow. This creates potential for arbitrary code execution, denial of service conditions, or privilege escalation within the device's operating environment. The vulnerability is particularly concerning because it only requires authentication to the device's administrative interface, which is often accessible via default credentials or credentials that have not been changed by users.
The operational impact of this vulnerability extends beyond simple device compromise as it affects the fundamental security posture of networks relying on these routers. An attacker who gains access to the administrative interface can potentially modify router configurations, redirect traffic through malicious servers, or establish persistent backdoors within the network infrastructure. The vulnerability enables privilege escalation attacks that could allow an authenticated user to gain root access to the device's operating system. Network security teams face significant challenges in identifying affected devices since the vulnerability exists in firmware versions that may be deployed across enterprise and residential networks. The impact is particularly severe in enterprise environments where multiple routers may be managed centrally, as compromise of a single device could potentially provide access to larger network segments.
Mitigation strategies should focus on immediate firmware updates from NETGEAR to address the buffer overflow conditions. Network administrators should ensure all affected devices are updated to the latest firmware versions that contain patches for this vulnerability. Additionally, implementing network segmentation and access controls can limit the potential impact if a device is compromised, while monitoring for unusual administrative access patterns or configuration changes can help detect exploitation attempts. The vulnerability aligns with ATT&CK technique T1068 which covers 'Exploitation for Privilege Escalation' and T1566 which addresses 'Phishing for Information' as attackers may attempt to gain initial access through credential compromise before exploiting this vulnerability. Organizations should also implement robust patch management processes to ensure timely deployment of security updates across all network infrastructure devices. Regular vulnerability scanning and network monitoring should be conducted to identify any devices that may not have been properly updated or may be running unsupported firmware versions.