CVE-2025-22952: Usememos Memos SSRF Vulnerability

CVE-2025-22952 Overview

CVE-2025-22952 is a critical Server-Side Request Forgery (SSRF) vulnerability discovered in elestio memos v0.23.0. The vulnerability stems from insufficient validation of user-supplied URLs, which can be exploited by attackers to perform SSRF attacks. This allows malicious actors to make the server initiate requests to arbitrary internal or external destinations, potentially exposing sensitive internal services, accessing cloud metadata endpoints, or pivoting to attack internal network resources.

Critical Impact

This SSRF vulnerability enables unauthenticated attackers to abuse the server as a proxy to access internal resources, potentially leading to exposure of sensitive data, internal service compromise, or further network reconnaissance.

Affected Products

• Usememos Memos v0.23.0
• elestio memos v0.23.0

Discovery Timeline

• 2025-02-27 - CVE-2025-22952 published to NVD
• 2025-07-10 - Last updated in NVD database

Technical Details for CVE-2025-22952

Vulnerability Analysis

This vulnerability is classified under CWE-918 (Server-Side Request Forgery). The core issue lies in the application's failure to properly validate and sanitize user-supplied URLs before using them to make server-side HTTP requests. When a user provides a URL, the application processes it without adequate checks, allowing attackers to craft malicious URLs that target internal services, cloud metadata endpoints (such as 169.254.169.254), or other restricted resources.

The vulnerability is particularly dangerous because it requires no authentication and can be exploited remotely over the network with low attack complexity. Successful exploitation could lead to unauthorized access to internal services, data exfiltration from cloud environments, or serve as a stepping stone for further attacks within the internal network.

Root Cause

The root cause of this vulnerability is the insufficient validation of user-supplied URLs within the memos application. The application accepts URL input from users and makes server-side requests without implementing proper allowlists, blocklists, or URL scheme restrictions. This lack of input validation allows attackers to specify arbitrary destinations including internal IP addresses, localhost references, and cloud metadata endpoints.

Attack Vector

The attack vector for CVE-2025-22952 is network-based, requiring no user interaction or prior authentication. An attacker can exploit this vulnerability by submitting specially crafted URLs through the vulnerable endpoint. The server then makes requests to the attacker-specified destination, effectively acting as a proxy.

Common exploitation scenarios include:

• Accessing cloud provider metadata services to retrieve instance credentials
• Scanning internal network services and ports
• Accessing internal APIs and administrative interfaces
• Bypassing firewall restrictions by routing requests through the vulnerable server
• Retrieving sensitive configuration files from internal services

The vulnerability can be exploited by crafting URLs that target internal resources such as http://localhost/admin, http://169.254.169.254/latest/meta-data/, or internal IP ranges like http://192.168.1.1/.

Detection Methods for CVE-2025-22952

Indicators of Compromise

• Unusual outbound HTTP requests from the memos server to internal IP addresses (e.g., 10.x.x.x, 172.16.x.x, 192.168.x.x)
• Server requests to cloud metadata endpoints (169.254.169.254)
• HTTP requests containing localhost or loopback addresses (127.0.0.1, ::1)
• Abnormal request patterns targeting internal service ports

Detection Strategies

• Monitor web application logs for URL parameters containing internal IP addresses or localhost references
• Implement network-level detection for outbound requests from the memos server to unexpected internal destinations
• Deploy web application firewalls (WAF) with SSRF detection rules
• Analyze DNS queries from the server for resolution of internal hostnames or suspicious domains

Monitoring Recommendations

• Enable detailed logging of all URL-related operations in the memos application
• Configure alerts for outbound connections from the application server to internal network ranges
• Monitor for requests to well-known cloud metadata IP addresses
• Track unusual HTTP response codes and connection timeouts that may indicate SSRF probing activity

How to Mitigate CVE-2025-22952

Immediate Actions Required

• Upgrade memos to a patched version that addresses the URL validation issue
• Apply the fix referenced in GitHub Pull Request #4428
• Implement network-level restrictions to prevent the server from accessing internal resources
• Review application logs for evidence of exploitation attempts

Patch Information

The vulnerability has been addressed by the usememos development team. The fix is tracked in GitHub Issue #4413 and the corresponding patch is available in GitHub Pull Request #4428. Organizations running memos v0.23.0 should upgrade to a patched version as soon as possible.

Workarounds

• Deploy a web application firewall (WAF) with SSRF protection rules in front of the memos application
• Configure network segmentation to restrict the memos server's ability to access internal services
• Implement egress filtering to block outbound connections from the server to internal IP ranges and cloud metadata endpoints
• Use a reverse proxy to filter and validate incoming URL parameters before they reach the application

If immediate patching is not feasible, the following network-level controls can help reduce risk:

# Configuration example
# Block outbound connections to internal networks and metadata endpoints
# Example iptables rules for the memos server

# Block access to cloud metadata endpoint
iptables -A OUTPUT -d 169.254.169.254 -j DROP

# Block access to private IP ranges
iptables -A OUTPUT -d 10.0.0.0/8 -j DROP
iptables -A OUTPUT -d 172.16.0.0/12 -j DROP
iptables -A OUTPUT -d 192.168.0.0/16 -j DROP

# Block localhost connections from application
iptables -A OUTPUT -d 127.0.0.0/8 -j DROP