CVE-2025-9395: wblog 0.0.1 SSRF Vulnerability

CVE-2025-9395 Overview

CVE-2025-9395 is a server-side request forgery (SSRF) vulnerability in wangsongyan wblog version 0.0.1. The flaw resides in the RestorePost function within backup.go. Attackers manipulate the fileName argument to coerce the server into issuing unintended outbound requests. The vulnerability is exploitable remotely over the network and requires low privileges. A public exploit disclosure exists, and the vendor did not respond to disclosure attempts. The weakness is classified under CWE-918: Server-Side Request Forgery.

Critical Impact
Authenticated remote attackers can abuse the RestorePost backup functionality to make the wblog server issue arbitrary requests, potentially reaching internal services or exposing limited confidentiality, integrity, and availability impact.

Affected Products

wangsongyan wblog 0.0.1
backup.go component, RestorePost function
Deployments exposing the wblog administrative backup endpoint

Discovery Timeline

2025-08-24 - CVE-2025-9395 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-9395

Vulnerability Analysis

The vulnerability affects the backup restoration workflow in wblog, a lightweight Go-based blog platform. The RestorePost handler in backup.go accepts a fileName parameter that is used to retrieve a resource without sufficient validation of the source location. An attacker who can reach the restore endpoint supplies a crafted value that redirects the request to an arbitrary URL or host of their choosing. The server then performs the outbound fetch on the attacker's behalf, which constitutes a classic server-side request forgery condition.

SSRF in a backup routine is particularly useful to attackers because the server often runs with network reach into private subnets. The flaw carries low confidentiality, integrity, and availability impact per the CVSS 4.0 vector, but it can be chained with internal services that trust loopback or private-range callers. The vendor was contacted but did not respond, and no patched release is currently published.

Root Cause

The root cause is missing validation and allow-listing on the fileName argument passed into RestorePost. The function treats attacker-supplied input as a trusted location for a backup artifact and dispatches a request without filtering schemes, hosts, or network ranges. This violates CWE-918 guidance to constrain outbound requests from server-side fetchers.

Attack Vector

Exploitation requires network access to the wblog instance and a low-privileged authenticated session capable of invoking the backup restore endpoint. The attacker submits a restore request where fileName references an attacker-controlled or internal URL. The server performs the request, and the attacker can observe responses, side effects, or timing to enumerate internal infrastructure. Public proof-of-concept details are available in the project's GitHub README vulnerability section.

No verified exploit code is reproduced here. Refer to the VulDB entry #321231 for additional technical context.

Detection Methods for CVE-2025-9395

Indicators of Compromise

Unexpected outbound HTTP or HTTPS requests from the wblog host targeting internal RFC1918 addresses, link-local metadata endpoints, or loopback.
Access log entries for the backup restore endpoint containing URL-like values in the fileName parameter.
Authenticated sessions invoking RestorePost from source IPs that do not match administrative activity patterns.

Detection Strategies

Inspect application and reverse-proxy logs for requests to the restore handler where fileName contains http://, https://, file://, or IP literals.
Correlate wblog process network telemetry with request handling to flag outbound connections initiated during a restore operation.
Alert on connections from the wblog host to cloud metadata services such as 169.254.169.254 or internal management subnets.

Monitoring Recommendations

Enable verbose access logging on the wblog administrative routes and forward logs to a centralized analytics platform.
Baseline normal outbound destinations for the wblog host and alert on deviations.
Monitor authentication events on the admin interface for brute force or credential stuffing that could precede exploitation.

How to Mitigate CVE-2025-9395

Immediate Actions Required

Restrict network access to the wblog administrative interface using IP allow-listing or a VPN.
Disable or remove the backup restore functionality if it is not required in production.
Rotate administrative credentials and enforce strong authentication for any account that can call RestorePost.
Place the wblog host behind an egress proxy that blocks requests to internal address ranges and cloud metadata endpoints.

Patch Information

No vendor patch is available at the time of writing. The project maintainer did not respond to the disclosure. Users should evaluate forking the repository and applying input validation to RestorePost, or migrating to an actively maintained blog platform. Track updates on the wblog GitHub repository.

Workarounds

Validate the fileName parameter against a strict allow-list of local filesystem paths and reject any value containing a URL scheme or host component.
Enforce egress firewall rules that prevent the wblog process from reaching private networks, loopback, or metadata services.
Deploy the application behind a web application firewall with rules that block SSRF payload patterns on the restore endpoint.
Run the wblog process under a least-privileged service account with no network reach to sensitive internal systems.

bash

# Example egress restriction using iptables to block RFC1918 and metadata targets from the wblog service user
sudo iptables -A OUTPUT -m owner --uid-owner wblog -d 169.254.169.254 -j REJECT
sudo iptables -A OUTPUT -m owner --uid-owner wblog -d 10.0.0.0/8 -j REJECT
sudo iptables -A OUTPUT -m owner --uid-owner wblog -d 172.16.0.0/12 -j REJECT
sudo iptables -A OUTPUT -m owner --uid-owner wblog -d 192.168.0.0/16 -j REJECT
sudo iptables -A OUTPUT -m owner --uid-owner wblog -d 127.0.0.0/8 -j REJECT