# GO-SSRF-002: SSRF via Outbound net/http Client Calls

> **Severity:** HIGH | **CWE:** CWE-918 | **OWASP:** A10:2021

- **Language:** Go
- **Category:** Security
- **URL:** https://codepathfinder.dev/registry/golang/security/GO-SSRF-002
- **Detection:** `pathfinder scan --ruleset golang/GO-SSRF-002 --project .`

## Description

This rule detects SSRF flows where user input from HTTP request parameters reaches Go's
standard library net/http client calls (http.Get, http.Post, http.Head, http.PostForm,
and http.Client.Do). These are the most common HTTP client patterns in Go applications.

**SSRF via net/http is particularly common** because many Go web services implement
"URL preview", "webhook registration", "avatar URL", or "external feed fetch" features
using net/http without considering that users can supply internal or metadata URLs.

**Go URL parsing edge cases** that bypass naive host-string matching:
- `url.Parse("http://169.254.169.254")` correctly identifies host as "169.254.169.254"
  but `url.Parse("http://169.254.169.254%2Flatest%2Fmeta-data")` or similar URL-encoded
  variants may bypass simple string comparison.
- "Protocol-relative URLs: `url.Parse(\"//169.254.169.254\")` has an empty Scheme field"
  but Host = "169.254.169.254" — validation that only checks Scheme may miss this.
- "IPv6-mapped IPv4: `http://[::ffff:169.254.169.254]` — url.Parse sets Host to"
  `[::ffff:169.254.169.254]`, which is equal to 169.254.169.254 when parsed as IP.

**Redirect following**: Go's http.Client follows redirects by default. An SSRF
prevention check that validates the initial URL but doesn't validate redirect targets
allows redirect-chain bypass: `https://attacker.com/redirect?to=http://169.254.169.254`.
Override `CheckRedirect` to validate each redirect destination.

Complements GO-SSRF-001 which covers go-resty client. Together these rules cover
the two most common Go HTTP client patterns.


## Vulnerable Code

```python
# --- file: vulnerable.go ---
// GO-SSRF-002 positive test cases — all SHOULD be detected
package main

import (
	"net/http"

	"github.com/gin-gonic/gin"
)

func ssrfHTTPGet(c *gin.Context) {
	url := c.Query("url")        // source
	http.Get(url)                // SINK: user-controlled outbound request
}

func ssrfHTTPPost(w http.ResponseWriter, r *http.Request) {
	endpoint := r.FormValue("endpoint") // source
	http.Post(endpoint, "application/json", nil) // SINK
}

func ssrfHTTPClientDo(c *gin.Context) {
	target := c.Query("target")  // source
	client := &http.Client{}
	req, _ := http.NewRequest("GET", target, nil) // SINK
	client.Do(req)
}

func ssrfHTTPGetFormValue(w http.ResponseWriter, r *http.Request) {
	host := r.FormValue("host")
	http.Get("http://" + host + "/api/data") // SINK
}

# --- file: go.mod ---
module example.com/go-ssrf-002/positive

go 1.25.0

require github.com/gin-gonic/gin v1.12.0

require (
	github.com/bytedance/gopkg v0.1.3 // indirect
	github.com/bytedance/sonic v1.15.0 // indirect
	github.com/bytedance/sonic/loader v0.5.0 // indirect
	github.com/cloudwego/base64x v0.1.6 // indirect
	github.com/gabriel-vasile/mimetype v1.4.12 // indirect
	github.com/gin-contrib/sse v1.1.0 // indirect
	github.com/go-playground/locales v0.14.1 // indirect
	github.com/go-playground/universal-translator v0.18.1 // indirect
	github.com/go-playground/validator/v10 v10.30.1 // indirect
	github.com/goccy/go-json v0.10.5 // indirect
	github.com/goccy/go-yaml v1.19.2 // indirect
	github.com/json-iterator/go v1.1.12 // indirect
	github.com/klauspost/cpuid/v2 v2.3.0 // indirect
	github.com/leodido/go-urn v1.4.0 // indirect
	github.com/mattn/go-isatty v0.0.20 // indirect
	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
	github.com/modern-go/reflect2 v1.0.2 // indirect
	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
	github.com/quic-go/qpack v0.6.0 // indirect
	github.com/quic-go/quic-go v0.59.0 // indirect
	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
	github.com/ugorji/go/codec v1.3.1 // indirect
	go.mongodb.org/mongo-driver/v2 v2.5.0 // indirect
	golang.org/x/arch v0.22.0 // indirect
	golang.org/x/crypto v0.48.0 // indirect
	golang.org/x/net v0.51.0 // indirect
	golang.org/x/sys v0.41.0 // indirect
	golang.org/x/text v0.34.0 // indirect
	google.golang.org/protobuf v1.36.10 // indirect
)

# --- file: go.sum ---
github.com/bytedance/gopkg v0.1.3 h1:TPBSwH8RsouGCBcMBktLt1AymVo2TVsBVCY4b6TnZ/M=
github.com/bytedance/gopkg v0.1.3/go.mod h1:576VvJ+eJgyCzdjS+c4+77QF3p7ubbtiKARP3TxducM=
github.com/bytedance/sonic v1.15.0 h1:/PXeWFaR5ElNcVE84U0dOHjiMHQOwNIx3K4ymzh/uSE=
github.com/bytedance/sonic v1.15.0/go.mod h1:tFkWrPz0/CUCLEF4ri4UkHekCIcdnkqXw9VduqpJh0k=
github.com/bytedance/sonic/loader v0.5.0 h1:gXH3KVnatgY7loH5/TkeVyXPfESoqSBSBEiDd5VjlgE=
github.com/bytedance/sonic/loader v0.5.0/go.mod h1:AR4NYCk5DdzZizZ5djGqQ92eEhCCcdf5x77udYiSJRo=
github.com/cloudwego/base64x v0.1.6 h1:t11wG9AECkCDk5fMSoxmufanudBtJ+/HemLstXDLI2M=
github.com/cloudwego/base64x v0.1.6/go.mod h1:OFcloc187FXDaYHvrNIjxSe8ncn0OOM8gEHfghB2IPU=
github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/gabriel-vasile/mimetype v1.4.12 h1:e9hWvmLYvtp846tLHam2o++qitpguFiYCKbn0w9jyqw=
github.com/gabriel-vasile/mimetype v1.4.12/go.mod h1:d+9Oxyo1wTzWdyVUPMmXFvp4F9tea18J8ufA774AB3s=
github.com/gin-contrib/sse v1.1.0 h1:n0w2GMuUpWDVp7qSpvze6fAu9iRxJY4Hmj6AmBOU05w=
github.com/gin-contrib/sse v1.1.0/go.mod h1:hxRZ5gVpWMT7Z0B0gSNYqqsSCNIJMjzvm6fqCz9vjwM=
github.com/gin-gonic/gin v1.12.0 h1:b3YAbrZtnf8N//yjKeU2+MQsh2mY5htkZidOM7O0wG8=
github.com/gin-gonic/gin v1.12.0/go.mod h1:VxccKfsSllpKshkBWgVgRniFFAzFb9csfngsqANjnLc=
github.com/go-playground/assert/v2 v2.2.0 h1:JvknZsQTYeFEAhQwI4qEt9cyV5ONwRHC+lYKSsYSR8s=
github.com/go-playground/assert/v2 v2.2.0/go.mod h1:VDjEfimB/XKnb+ZQfWdccd7VUvScMdVu0Titje2rxJ4=
github.com/go-playground/locales v0.14.1 h1:EWaQ/wswjilfKLTECiXz7Rh+3BjFhfDFKv/oXslEjJA=
github.com/go-playground/locales v0.14.1/go.mod h1:hxrqLVvrK65+Rwrd5Fc6F2O76J/NuW9t0sjnWqG1slY=
github.com/go-playground/universal-translator v0.18.1 h1:Bcnm0ZwsGyWbCzImXv+pAJnYK9S473LQFuzCbDbfSFY=
github.com/go-playground/universal-translator v0.18.1/go.mod h1:xekY+UJKNuX9WP91TpwSH2VMlDf28Uj24BCp08ZFTUY=
github.com/go-playground/validator/v10 v10.30.1 h1:f3zDSN/zOma+w6+1Wswgd9fLkdwy06ntQJp0BBvFG0w=
github.com/go-playground/validator/v10 v10.30.1/go.mod h1:oSuBIQzuJxL//3MelwSLD5hc2Tu889bF0Idm9Dg26cM=
github.com/goccy/go-json v0.10.5 h1:Fq85nIqj+gXn/S5ahsiTlK3TmC85qgirsdTP/+DeaC4=
github.com/goccy/go-json v0.10.5/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PULtXL6M=
github.com/goccy/go-yaml v1.19.2 h1:PmFC1S6h8ljIz6gMRBopkjP1TVT7xuwrButHID66PoM=
github.com/goccy/go-yaml v1.19.2/go.mod h1:XBurs7gK8ATbW4ZPGKgcbrY1Br56PdM69F7LkFRi1kA=
github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
github.com/klauspost/cpuid/v2 v2.3.0 h1:S4CRMLnYUhGeDFDqkGriYKdfoFlDnMtqTiI/sFzhA9Y=
github.com/klauspost/cpuid/v2 v2.3.0/go.mod h1:hqwkgyIinND0mEev00jJYCxPNVRVXFQeu1XKlok6oO0=
github.com/leodido/go-urn v1.4.0 h1:WT9HwE9SGECu3lg4d/dIA+jxlljEa1/ffXKmRjqdmIQ=
github.com/leodido/go-urn v1.4.0/go.mod h1:bvxc+MVxLKB4z00jd1z+Dvzr47oO32F/QSNjSBOlFxI=
github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd h1:TRLaZ9cD/w8PVh93nsPXa1VrQ6jlwL5oN8l14QlcNfg=
github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9Gz0M=
github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
github.com/pelletier/go-toml/v2 v2.2.4 h1:mye9XuhQ6gvn5h28+VilKrrPoQVanw5PMw/TB0t5Ec4=
github.com/pelletier/go-toml/v2 v2.2.4/go.mod h1:2gIqNv+qfxSVS7cM2xJQKtLSTLUE9V8t9Stt+h56mCY=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/quic-go/qpack v0.6.0 h1:g7W+BMYynC1LbYLSqRt8PBg5Tgwxn214ZZR34VIOjz8=
github.com/quic-go/qpack v0.6.0/go.mod h1:lUpLKChi8njB4ty2bFLX2x4gzDqXwUpaO1DP9qMDZII=
github.com/quic-go/quic-go v0.59.0 h1:OLJkp1Mlm/aS7dpKgTc6cnpynnD2Xg7C1pwL6vy/SAw=
github.com/quic-go/quic-go v0.59.0/go.mod h1:upnsH4Ju1YkqpLXC305eW3yDZ4NfnNbmQRCMWS58IKU=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
github.com/stretchr/objx v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA=
github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
github.com/twitchyliquid64/golang-asm v0.15.1 h1:SU5vSMR7hnwNxj24w34ZyCi/FmDZTkS4MhqMhdFk5YI=
github.com/twitchyliquid64/golang-asm v0.15.1/go.mod h1:a1lVb/DtPvCB8fslRZhAngC2+aY1QWCk3Cedj/Gdt08=
github.com/ugorji/go/codec v1.3.1 h1:waO7eEiFDwidsBN6agj1vJQ4AG7lh2yqXyOXqhgQuyY=
github.com/ugorji/go/codec v1.3.1/go.mod h1:pRBVtBSKl77K30Bv8R2P+cLSGaTtex6fsA2Wjqmfxj4=
go.mongodb.org/mongo-driver/v2 v2.5.0 h1:yXUhImUjjAInNcpTcAlPHiT7bIXhshCTL3jVBkF3xaE=
go.mongodb.org/mongo-driver/v2 v2.5.0/go.mod h1:yOI9kBsufol30iFsl1slpdq1I0eHPzybRWdyYUs8K/0=
go.uber.org/mock v0.6.0 h1:hyF9dfmbgIX5EfOdasqLsWD6xqpNZlXblLB/Dbnwv3Y=
go.uber.org/mock v0.6.0/go.mod h1:KiVJ4BqZJaMj4svdfmHM0AUx4NJYO8ZNpPnZn1Z+BBU=
golang.org/x/arch v0.22.0 h1:c/Zle32i5ttqRXjdLyyHZESLD/bB90DCU1g9l/0YBDI=
golang.org/x/arch v0.22.0/go.mod h1:dNHoOeKiyja7GTvF9NJS1l3Z2yntpQNzgrjh1cU103A=
golang.org/x/crypto v0.48.0 h1:/VRzVqiRSggnhY7gNRxPauEQ5Drw9haKdM0jqfcCFts=
golang.org/x/crypto v0.48.0/go.mod h1:r0kV5h3qnFPlQnBSrULhlsRfryS2pmewsg+XfMgkVos=
golang.org/x/net v0.51.0 h1:94R/GTO7mt3/4wIKpcR5gkGmRLOuE/2hNGeWq/GBIFo=
golang.org/x/net v0.51.0/go.mod h1:aamm+2QF5ogm02fjy5Bb7CQ0WMt1/WVM7FtyaTLlA9Y=
golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.41.0 h1:Ivj+2Cp/ylzLiEU89QhWblYnOE9zerudt9Ftecq2C6k=
golang.org/x/sys v0.41.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
golang.org/x/text v0.34.0 h1:oL/Qq0Kdaqxa1KbNeMKwQq0reLCCaFtqu2eNuSeNHbk=
golang.org/x/text v0.34.0/go.mod h1:homfLqTYRFyVYemLBFl5GgL/DWEiH5wcsQ5gSh1yziA=
google.golang.org/protobuf v1.36.10 h1:AYd7cD/uASjIL6Q9LiTjz8JLcrh/88q5UObnmY3aOOE=
google.golang.org/protobuf v1.36.10/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
```

## Secure Code

```python
// SECURE: allowlist + resolved IP validation + redirect control
import (
    "context"
    "net"
    "net/http"
    "net/url"
)

var allowedHosts = map[string]bool{
    "api.partner.com":  true,
    "cdn.example.com":  true,
}

func isPrivateIP(ip net.IP) bool {
    for _, cidr := range []string{
        "10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16",
        "127.0.0.0/8", "169.254.0.0/16", "::1/128", "fc00::/7",
    } {
        _, network, _ := net.ParseCIDR(cidr)
        if network.Contains(ip) {
            return true
        }
    }
    return false
}

func safeHTTPClient() *http.Client {
    // Custom dialer that validates resolved IPs before connecting
    dialer := &net.Dialer{}
    transport := &http.Transport{
        DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
            host, port, _ := net.SplitHostPort(addr)
            ips, err := net.DefaultResolver.LookupHost(ctx, host)
            if err != nil {
                return nil, fmt.Errorf("DNS resolution failed")
            }
            for _, ip := range ips {
                if isPrivateIP(net.ParseIP(ip)) {
                    return nil, fmt.Errorf("IP %s is in a private range", ip)
                }
            }
            return dialer.DialContext(ctx, network, net.JoinHostPort(ips[0], port))
        },
    }
    return &http.Client{
        Transport: transport,
        Timeout:   10 * time.Second,
        // Validate redirect targets too
        CheckRedirect: func(req *http.Request, via []*http.Request) error {
            if !allowedHosts[req.URL.Hostname()] {
                return fmt.Errorf("redirect to non-allowlisted host: %s", req.URL.Host)
            }
            return nil
        },
    }
}

func fetchURL(w http.ResponseWriter, r *http.Request) {
    rawURL := r.FormValue("url")
    parsed, err := url.Parse(rawURL)
    if err != nil || !allowedHosts[parsed.Hostname()] {
        http.Error(w, "invalid or disallowed URL", 400)
        return
    }
    client := safeHTTPClient()
    resp, err := client.Get(rawURL)
    // ...
}

```

## Detection Rule (Python SDK)

```python
"""GO-SSRF-002: SSRF via HTTP request input reaching outbound net/http client calls."""

from codepathfinder.go_rule import (
    GoGinContext,
    GoHTTPRequest,
    GoHTTPClient,
    GoEchoContext,
    GoFiberCtx,
)
from codepathfinder import flows
from codepathfinder.presets import PropagationPresets
from codepathfinder.go_decorators import go_rule


@go_rule(
    id="GO-SSRF-002",
    severity="HIGH",
    cwe="CWE-918",
    owasp="A10:2021",
    tags="go,security,ssrf,net-http,CWE-918,OWASP-A10",
    message=(
        "User-controlled input flows into net/http client methods (http.Get, http.Post, "
        "http.NewRequest, client.Do). This creates a Server-Side Request Forgery (SSRF) "
        "vulnerability. Attackers can route requests to internal services, cloud metadata "
        "endpoints, or arbitrary hosts. Validate the URL host against an allowlist."
    ),
)
def go_ssrf_http_client():
    """HTTP request input reaches outbound net/http client — SSRF."""
    return flows(
        from_sources=[
            GoGinContext.method(
                "Param", "Query", "PostForm", "GetRawData",
                "ShouldBindJSON", "BindJSON", "GetHeader"
            ),
            GoEchoContext.method("QueryParam", "FormValue", "Param"),
            GoFiberCtx.method("Params", "Query", "FormValue", "Get"),
            GoHTTPRequest.method("FormValue", "PostFormValue"),
            GoHTTPRequest.attr("Body", "URL.Path", "URL.RawQuery"),
        ],
        to_sinks=[
            GoHTTPClient.method("Get", "Post", "Do", "Head", "PostForm"),
        ],
        propagates_through=PropagationPresets.standard(),
        scope="global",
    )
```

## How to Fix

- Validate outbound URL hosts against a strict allowlist.
- After DNS resolution, verify resolved IPs are not in private ranges.
- Override http.Client.CheckRedirect to validate redirect destinations.
- Disable redirects entirely if not needed: CheckRedirect returning http.ErrUseLastResponse.
- Set connection timeouts to prevent slow-loris-style attacks on SSRF targets.
- Enable AWS IMDSv2 to require session tokens for metadata access.

## Security Implications

- **AWS IAM Credential Exfiltration:** `http.Get("http://169.254.169.254/latest/meta-data/iam/security-credentials/<role>")`
returns temporary AWS credentials when IMDSv1 is enabled. With these credentials,
attackers can access any AWS service the instance role permits.

- **Internal Network Reconnaissance:** By varying IP and port in the target URL, attackers map internal services.
HTTP response status codes and timing reveal which ports are open and what
services respond.

- **Kubernetes API Server Access:** `http.Get("https://kubernetes.default.svc/api/v1/secrets")` with a valid service
account token (if mounted) reveals secrets across the namespace or cluster.


## References

- [CWE-918: Server-Side Request Forgery — MITRE](https://cwe.mitre.org/data/definitions/918.html)
- [OWASP SSRF Prevention Cheat Sheet](https://cheatsheetseries.owasp.org/cheatsheets/Server_Side_Request_Forgery_Prevention_Cheat_Sheet.html)
- [Go net/http package documentation](https://pkg.go.dev/net/http)
- [AWS IMDSv2 — requiring session tokens for metadata access](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/configuring-instance-metadata-service.html)
- [GCP metadata server documentation](https://cloud.google.com/compute/docs/metadata/overview)
- [RFC 3986 — Uniform Resource Identifier (URI)](https://www.rfc-editor.org/rfc/rfc3986)

---

Source: https://codepathfinder.dev/registry/golang/security/GO-SSRF-002
Code Pathfinder — Open source, type-aware SAST with cross-file dataflow analysis