CVE-2022-25876 in link-preview-js
Summary
by MITRE • 07/02/2022
The package link-preview-js before 2.1.16 are vulnerable to Server-side Request Forgery (SSRF) which allows attackers to send arbitrary requests to the local network and read the response. This is due to flawed DNS rebinding protection.
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Analysis
by VulDB Data Team • 07/18/2022
The vulnerability identified as CVE-2022-25876 affects the link-preview-js package version 2.1.15 and earlier, presenting a critical server-side request forgery flaw that enables attackers to bypass network restrictions and access internal resources. This vulnerability resides in the package's DNS rebinding protection mechanism which fails to properly validate or sanitize network requests, creating an avenue for malicious actors to exploit the application's network connectivity. The flaw specifically targets the package's ability to fetch metadata from URLs, which is a core functionality designed to generate previews of web links. When the package processes a URL, it attempts to resolve DNS records and establish connections to various endpoints, but the inadequate protection allows unauthorized access to internal network services that should remain isolated from external requests.
The technical implementation of this vulnerability stems from the package's flawed DNS rebinding protection logic that does not adequately validate the target hosts or IP addresses that the application attempts to connect to. This protection mechanism is intended to prevent attackers from making requests to internal services by checking DNS resolution results against expected patterns or network boundaries. However, the implementation contains a critical flaw where the validation process can be bypassed through specific request manipulation techniques. The vulnerability allows attackers to construct URLs that, when processed by the package, result in connections being made to internal IP addresses or services that are normally protected by network firewalls or access controls. This represents a direct violation of network isolation principles and can lead to unauthorized access to sensitive internal systems.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can enable attackers to perform reconnaissance on internal network infrastructure and potentially escalate privileges through access to internal services. An attacker can leverage this flaw to probe internal network segments, identify running services, and potentially gain access to sensitive databases, administrative interfaces, or other internal resources that are not directly exposed to the internet. The vulnerability is particularly dangerous in environments where applications using this package are deployed in cloud or containerized environments, as it can allow attackers to bypass security controls that are typically in place to protect internal services. The attack surface includes any application that utilizes the link-preview-js package to generate previews for user-provided URLs, making it a widespread concern across various web applications and services.
Mitigation strategies for CVE-2022-25876 should prioritize immediate patching of the link-preview-js package to version 2.1.16 or later, which contains the necessary fixes for the DNS rebinding protection mechanism. Organizations should also implement network-level controls such as firewall rules to restrict outbound connections from applications that use this package, particularly preventing access to private IP ranges and internal services. Additionally, application-level restrictions should be implemented to validate and sanitize all input URLs before processing them through the link-preview functionality. The fix addresses the underlying CWE-444 vulnerability category related to improper handling of HTTP requests and DNS rebinding protection failures, which aligns with ATT&CK technique T1071.004 for application layer protocol traffic. Security teams should also consider implementing monitoring and alerting for unusual outbound network connections from applications using this package, as well as conducting regular vulnerability assessments to identify other potentially affected components that may be using similar DNS rebinding protection patterns.