CVE-2017-5868 Scanner

OpenVPN Access Server is used by businesses and individuals to establish secure VPN connections over the internet. Deployed widely by IT teams and security professionals, it enables remote access and secure communication within a network. Its interface is web-based, providing users with the convenience of managing their connections online. OpenVPN Access Server is especially popular among organizations that prioritize secure, encrypted remote access solutions. The platform’s broad compatibility and reliable encryption standards make it a trusted choice across industries.

This CRLF Injection vulnerability allows attackers to insert arbitrary HTTP headers by injecting %0A characters into HTTP requests. Malicious actors can exploit this flaw to manipulate session cookies or conduct HTTP response splitting attacks. As a result, session fixation attacks may occur, compromising user sessions and security. Addressing this vulnerability is critical to maintaining a secure and trustworthy access platform.

The vulnerability lies in the way OpenVPN Access Server 2.1.4 processes HTTP requests within its web interface, particularly through the __session_start__/ endpoint. When %0A characters are inserted in the PATH_INFO, an attacker can force the server to set custom headers. This response modification capability allows an attacker to fixate sessions or split HTTP responses to manipulate downstream interactions. Vulnerable parameters include header injection, which is particularly susceptible in this version. This behavior can expose sensitive data and lead to security degradation if left unaddressed.

If exploited, this vulnerability allows attackers to conduct session fixation attacks, leading to unauthorized access and potential data exposure. The CRLF Injection may also enable HTTP response splitting, which could cause users to be redirected to malicious sites or expose sensitive information within headers. Additionally, it may compromise the integrity of legitimate user sessions, posing a high risk to user trust and data security. Exploited extensively, this vulnerability could impact the broader network security.

S4E offers a robust solution for detecting and managing vulnerabilities like CRLF Injection in widely used software such as OpenVPN Access Server. By joining the platform, users can actively monitor, detect, and receive actionable insights on their assets, helping to mitigate risks before they become threats. SecurityForEveryone’s streamlined interface and prompt alert system ensure real-time visibility and efficient response options. Protect your systems effectively with comprehensive exposure management that prioritizes your digital security and peace of mind.

References:

• https://www.openwall.com/lists/oss-security/2017/05/23/13
• http://www.securitytracker.com/id/1038547
• https://nvd.nist.gov/vuln/detail/CVE-2017-5868