CVE-2025-0182 in danswer
Summary
by MITRE • 03/20/2025
A vulnerability in danswer-ai/danswer version 0.9.0 allows for denial of service through memory exhaustion. The issue arises from the use of a vulnerable version of the starlette package (<=0.49) via fastapi, which was patched in fastapi version 0.115.3. The vulnerability can be exploited by sending multiple requests to the /auth/saml/callback endpoint, leading to uncontrolled memory consumption and eventual denial of service.
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Analysis
by VulDB Data Team • 03/20/2025
The vulnerability identified as CVE-2025-0182 represents a critical denial of service flaw within the danswer-ai/danswer application version 0.9.0. This weakness stems from an outdated dependency chain that incorporates a vulnerable version of the starlette web framework, specifically versions equal to or below 0.49. The affected system utilizes fastapi as its primary web framework, which in turn depends on starlette for core functionality. When the application processes requests through the /auth/saml/callback endpoint, it becomes susceptible to memory exhaustion attacks that can ultimately lead to complete service disruption. The root cause of this vulnerability lies in the improper handling of request processing within the authentication flow, where memory allocation occurs without adequate bounds checking or resource limiting mechanisms. This flaw creates a pathway for attackers to consume excessive system resources through carefully crafted request sequences that exploit the underlying framework's memory management deficiencies.
The technical exploitation of this vulnerability occurs through a specifically targeted attack vector that focuses on the SAML authentication callback endpoint within the application's authentication system. When multiple concurrent requests are sent to the /auth/saml/callback endpoint, the vulnerable starlette implementation fails to properly manage memory allocation for each request processing cycle. This leads to uncontrolled memory growth as each request consumes additional heap space without proper cleanup or resource limits. The vulnerability manifests as a gradual increase in memory consumption that can quickly exhaust available system resources, causing the application to become unresponsive or crash entirely. The attack requires relatively simple request crafting that can be automated, making it particularly dangerous as it can be executed by unauthorized users without requiring elevated privileges or specialized knowledge beyond basic web application testing techniques.
The operational impact of CVE-2025-0182 extends beyond simple service disruption to potentially compromise the entire availability of the danswer-ai/danswer platform. Organizations relying on this application for document management, search capabilities, and AI-powered content analysis face significant risk of operational downtime that can last from minutes to hours depending on system resources and attack intensity. The vulnerability affects the core authentication functionality of the platform, which means that legitimate users may be unable to access the system through SAML-based authentication methods. This creates cascading effects throughout the organization's information systems, as the platform may serve as a central hub for various document processing and retrieval functions. The memory exhaustion can also impact system stability by causing the application server to become unresponsive, potentially affecting other services running on the same infrastructure through resource contention issues.
The remediation strategy for this vulnerability requires immediate attention to update the affected dependencies to versions that contain the necessary security patches. Organizations must upgrade their fastapi installation to version 0.115.3 or later, which includes the patched starlette component that resolves the memory handling issues. This update process should be performed carefully to ensure compatibility with existing application code and configurations. Additionally, implementing rate limiting and request throttling mechanisms at the network level can provide temporary protection while the dependency updates are being deployed. Security teams should also consider implementing memory monitoring and alerting systems to detect unusual memory consumption patterns that may indicate exploitation attempts. The vulnerability aligns with CWE-400 which specifically addresses unchecked resource consumption and represents a classic example of how outdated dependencies can create systemic security weaknesses within modern web applications. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique related to network denial of service and demonstrates how application-level flaws can be leveraged to achieve system-wide availability compromise through resource exhaustion attacks.