CVE-2023-30802 identifies a source code disclosure vulnerability in Sangfor Net-Gen Application Firewall version 8.0.17. The vulnerability arises from improper handling of HTTP requests containing an invalid Content-Length header, which can be exploited remotely without authentication. By sending such crafted HTTP requests, an attacker can retrieve PHP source code files from the firewall, exposing sensitive information such as credentials, configuration details, or proprietary logic embedded within the source. This type of vulnerability is classified under CWE-540, which involves the inclusion of sensitive information in source code that should not be publicly accessible. The flaw does not require user interaction and can be triggered over the network, increasing its risk profile. Although no public exploits have been reported yet, the ease of exploitation and the sensitive nature of the disclosed data make this a significant concern. The vulnerability impacts confidentiality but does not affect the integrity or availability of the firewall. Sangfor has not yet published a patch or mitigation guidance as of the provided data, so affected organizations must monitor for updates and consider interim protective measures. Given the firewall’s role in protecting network traffic, disclosure of its source code can facilitate further targeted attacks or bypass attempts by revealing internal logic and security mechanisms.

For European organizations, this vulnerability poses a risk of sensitive information leakage from the Sangfor Net-Gen Application Firewall, potentially exposing internal firewall logic, credentials, or configuration details. Such exposure can aid attackers in crafting more effective attacks, including evasion of firewall rules or lateral movement within networks. Organizations in critical infrastructure sectors (e.g., energy, finance, telecommunications) that deploy Sangfor firewalls may face increased risk of targeted attacks leveraging this vulnerability. The confidentiality breach could lead to compliance issues under GDPR if personal or sensitive data is indirectly exposed. Although the vulnerability does not directly disrupt service availability or data integrity, the indirect consequences of information disclosure can be severe, including facilitating subsequent attacks or unauthorized access. The lack of authentication and user interaction requirements means attackers can exploit this vulnerability remotely and at scale if the firewall is exposed to untrusted networks.

Immediate mitigation steps include restricting external network access to the Sangfor Net-Gen Application Firewall management interfaces and administrative endpoints to trusted internal networks only. Network-level filtering should be applied to block malformed HTTP requests, particularly those with suspicious or invalid Content-Length headers. Organizations should implement strict monitoring and alerting for anomalous HTTP traffic patterns targeting the firewall. Until an official patch is released, consider deploying web application firewalls or intrusion prevention systems to detect and block exploitation attempts. Conduct a thorough audit of firewall configurations and logs to identify any signs of exploitation. Engage with Sangfor support to obtain timelines for patches or recommended workarounds. Additionally, review and rotate any credentials or secrets that may have been exposed due to this vulnerability. Incorporate this vulnerability into vulnerability management and incident response plans to ensure rapid detection and remediation.