CVE-2024-35538 in Typecho
Summary
by MITRE • 08/20/2024
Typecho v1.3.0 was discovered to contain a Client IP Spoofing vulnerability, which allows attackers to falsify their IP addresses by specifying an arbitrary IP as value of X-Forwarded-For or Client-Ip headers while performing HTTP requests.
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Analysis
by VulDB Data Team • 08/21/2024
The vulnerability identified as CVE-2024-35538 affects Typecho version 1.3.0 and represents a significant client IP spoofing flaw that undermines the integrity of network traffic identification within the application. This issue manifests through the improper handling of HTTP headers, specifically the X-Forwarded-For and Client-Ip headers, which are commonly used by web applications to determine the original IP address of clients connecting through proxies or load balancers. The vulnerability stems from the application's failure to properly validate or sanitize these headers, allowing malicious actors to inject arbitrary IP addresses that can be interpreted as legitimate client addresses by the system.
From a technical perspective, this vulnerability operates at the application layer where HTTP request processing occurs, making it particularly dangerous in environments where IP-based access controls or logging mechanisms are implemented. The flaw essentially allows an attacker to manipulate the perceived source IP address of their requests, potentially bypassing IP-based restrictions, circumventing rate limiting mechanisms, or evading security controls that rely on accurate IP address identification. This type of vulnerability is classified under CWE-284 Access Control Issues, specifically related to improper access control enforcement when dealing with forwarded IP addresses. The attack vector leverages the standard HTTP header mechanisms used in proxy configurations, making it a common pattern in web application security flaws where applications trust headers without proper validation.
The operational impact of this vulnerability extends beyond simple IP address manipulation, as it can enable more sophisticated attacks including but not limited to access control bypasses, denial of service conditions, and the circumvention of security monitoring systems. In a production environment, this flaw could allow unauthorized users to appear as legitimate clients from trusted IP ranges, potentially gaining access to restricted resources or services. Security systems that depend on accurate IP logging for audit trails or intrusion detection may produce misleading information, complicating forensic analysis and incident response efforts. The vulnerability is particularly concerning in multi-tiered network architectures where Typecho might be deployed behind load balancers or reverse proxies, as attackers could exploit this weakness to appear as if they are connecting from trusted internal network segments rather than external malicious sources.
Mitigation strategies for CVE-2024-35538 should focus on implementing proper header validation and sanitization within the Typecho application. Organizations should configure the application to either ignore or properly validate the X-Forwarded-For and Client-Ip headers, ensuring that only trusted proxy servers can provide these values. The recommended approach involves implementing a whitelist of trusted proxy IP addresses and validating that forwarded headers originate from these known sources. Additionally, security controls should be implemented at the network level to prevent unauthorized modification of these headers, including the use of network firewalls or web application firewalls to filter malicious header values. The ATT&CK framework categorizes this vulnerability under T1566 Credential Access and T1071 Application Layer Protocol, highlighting the need for comprehensive network security controls. Organizations should also consider implementing IP address monitoring and logging that includes verification mechanisms to detect suspicious header manipulations. Regular security assessments and code reviews should be conducted to ensure that similar vulnerabilities are not present in other header handling mechanisms within the application, as this represents a broader class of issues related to trust relationships in distributed web applications.