CVE-2021-40413 in RLC-410W
Summary
by MITRE • 01/28/2022
An incorrect default permission vulnerability exists in the cgiserver.cgi cgi_check_ability functionality of reolink RLC-410W v3.0.0.136_20121102. The UpgradePrepare is the API that checks if a provided filename identifies a new version of the RLC-410W firmware. If the version is new, it would be possible, allegedly, to later on perform the Upgrade. An attacker can send an HTTP request to trigger this vulnerability.
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Analysis
by VulDB Data Team • 02/02/2022
The CVE-2021-40413 vulnerability represents a critical access control flaw within the reolink RLC-410W security camera firmware version 3.0.0.136_20121102. This issue manifests in the cgiserver.cgi component's cgi_check_ability functionality, specifically within the UpgradePrepare API implementation. The vulnerability stems from improper default permissions that allow unauthorized users to bypass authentication mechanisms required for firmware upgrade operations. The affected device operates under a web-based management interface that exposes the UpgradePrepare endpoint, which should normally validate firmware file integrity and authenticity before permitting upgrades. However, the default permission settings fail to properly restrict access to this critical functionality, creating a path for malicious actors to exploit the system's upgrade mechanism.
The technical exploitation of this vulnerability occurs through crafted HTTP requests that target the UpgradePrepare API endpoint. Attackers can construct specific HTTP requests that bypass the intended authentication checks, potentially allowing them to upload and install arbitrary firmware images on the device. This flaw operates at the application layer and directly violates security principles outlined in CWE-284, which addresses improper access control vulnerabilities. The vulnerability essentially creates a backdoor path for privilege escalation, as the UpgradePrepare function should only be accessible to authenticated administrators with proper authorization levels. The implementation fails to enforce proper session validation or authentication tokens, making it possible for unauthenticated users to trigger the firmware upgrade process.
From an operational standpoint, this vulnerability poses significant risks to network security and device integrity. The RLC-410W cameras are typically deployed in security monitoring environments where unauthorized access could lead to complete device compromise and potential network infiltration. Attackers could exploit this vulnerability to install malicious firmware that could provide persistent access to the device, enable data exfiltration, or disrupt security monitoring operations. The impact extends beyond individual device compromise as these cameras often form part of larger security infrastructures where a single compromised device could serve as a foothold for broader network attacks. This vulnerability aligns with ATT&CK technique T1072, which covers software deployment methods, and T1547, related to persistence mechanisms through legitimate system processes.
The remediation approach requires immediate implementation of proper access controls and authentication enforcement within the firmware upgrade functionality. Device manufacturers should implement mandatory authentication checks for all firmware-related operations, including the UpgradePrepare API endpoint. Security patches should enforce proper session management and token validation before allowing any firmware upgrade operations. Network administrators should conduct immediate vulnerability assessments of all deployed RLC-410W devices and implement network segmentation to limit exposure. The fix should address the root cause by ensuring that only authenticated administrators with appropriate privileges can access the UpgradePrepare functionality, thereby preventing unauthorized firmware installations that could compromise device security and network integrity.