CVE-2023-46229 in LangChain
Summary
by MITRE • 10/25/2023
LangChain before 0.0.317 allows SSRF via document_loaders/recursive_url_loader.py because crawling can proceed from an external server to an internal server.
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Analysis
by VulDB Data Team • 11/11/2023
The vulnerability identified as CVE-2023-46229 represents a critical server-side request forgery flaw within the LangChain framework version 0.0.317 and earlier. This issue specifically affects the document_loaders/recursive_url_loader.py module which enables recursive web crawling capabilities. The vulnerability arises from insufficient validation of URLs during the document loading process, allowing malicious actors to manipulate the crawler to make requests to internal network resources that should otherwise remain inaccessible from external networks. This represents a classic SSRF attack vector where external adversaries can leverage the application's legitimate functionality to probe internal systems.
The technical implementation of this vulnerability stems from the recursive URL loader's failure to properly sanitize and validate input URLs before initiating HTTP requests. When LangChain processes documents through the recursive URL loader, it accepts any URL provided in the input without adequate checks to prevent access to internal network addresses. This includes URLs that resolve to private IP ranges such as 10.x.x.x, 172.16.x.x through 172.31.x.x, or 192.168.x.x addresses that are typically protected by network firewalls and access controls. The flaw enables attackers to construct malicious URLs that bypass normal network security boundaries, potentially allowing them to access internal services, databases, or other sensitive resources that are not directly exposed to the internet.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can enable attackers to perform reconnaissance activities against internal network infrastructure. An attacker could use this vulnerability to enumerate internal services, potentially identifying running applications, open ports, and even sensitive endpoints that should remain hidden from external access. The recursive nature of the loader means that a single malicious input can trigger multiple requests to various internal targets, amplifying the reconnaissance capabilities. This vulnerability aligns with CWE-918, which specifically addresses Server-Side Request Forgery vulnerabilities where applications fail to validate URLs before making requests to external systems. The attack pattern follows common techniques described in the MITRE ATT&CK framework under T1018, which covers Valid Accounts and T1046, which covers Network Service Scanning.
Organizations utilizing LangChain frameworks must implement immediate mitigations to address this vulnerability. The most effective approach involves upgrading to LangChain version 0.0.317 or later where the SSRF protections have been implemented. Additionally, administrators should consider implementing network-level restrictions that prevent outbound connections from the LangChain application to internal network segments. Input validation should be enforced at multiple layers including application-level URL sanitization, network-level firewall rules, and potentially implementing a whitelist of allowed domains. The implementation of proper network segmentation and the use of network monitoring tools can help detect anomalous outbound requests that might indicate exploitation attempts. Security teams should also consider implementing runtime application self-protection mechanisms that can detect and block suspicious URL patterns during document loading operations, as this vulnerability demonstrates how legitimate application features can be abused for malicious purposes.