CVE-2019-20670 in RBR50
Summary
by MITRE
Certain NETGEAR devices are affected by stored XSS. This affects RBR50 before 2.3.5.30, RBS50 before 2.3.5.30, and RBK50 before 2.3.5.30.
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Analysis
by VulDB Data Team • 05/26/2024
The vulnerability identified as CVE-2019-20670 represents a critical stored cross-site scripting flaw affecting multiple NETGEAR router models including RBR50 RBS50 and RBK50 series. This vulnerability resides in the web-based management interface of these networking devices and allows attackers to inject malicious scripts that persist within the device's storage mechanisms. The affected firmware versions prior to 2.3.5.30 demonstrate insufficient input validation and output encoding practices that enable persistent script execution when legitimate users interact with compromised administrative interfaces.
The technical implementation of this vulnerability stems from inadequate sanitization of user-supplied input within the device's web administration portal. When administrators or authenticated users access certain management pages, the maliciously stored scripts execute within the context of the victim's browser session. This stored XSS condition occurs because the device fails to properly encode or escape user-controllable data before rendering it in web responses. The flaw typically manifests when attackers exploit form fields or parameter inputs that are subsequently displayed without proper security measures. According to CWE classification this vulnerability maps to CWE-79 which specifically addresses cross-site scripting flaws where untrusted data is improperly handled during web page generation.
The operational impact of this vulnerability extends beyond simple script injection as it provides attackers with the capability to establish persistent footholds within corporate or residential networks. An attacker who successfully exploits this vulnerability can execute arbitrary scripts in the context of authenticated users' browsers, potentially leading to session hijacking credential theft or unauthorized configuration changes. The stored nature of the vulnerability means that the malicious payload remains active even after the initial injection, continuously affecting any user who accesses the compromised management interface. Network administrators may remain unaware of the compromise until unusual network behavior or security incidents occur, as the malicious scripts operate transparently within the normal administrative interface.
Mitigation strategies for CVE-2019-20670 primarily focus on firmware updates and network segmentation measures. NETGEAR has released firmware versions 2.3.5.30 and later that address this vulnerability through improved input validation and output encoding mechanisms. Organizations should immediately deploy these updates across all affected device models to eliminate the stored XSS threat. Additional protective measures include implementing network access controls to restrict administrative interface access to trusted networks only, utilizing strong authentication mechanisms, and monitoring network traffic for suspicious activity. From an ATT&CK framework perspective this vulnerability aligns with techniques involving credential access and privilege escalation through web application exploitation, making it a significant concern for organizations following MITRE ATT&CK matrix classifications for network security assessments and threat modeling activities.