Add vpatch-CVE-2026-73570 rule and test

.appsec-tests/vpatch-CVE-2026-73570/CVE-2026-73570.yaml

@@ -0,0 +1,25 @@
+## autogenerated on 2026-09-17 09:30:13
+id: CVE-2026-73570
+info:
+  name: CVE-2026-73570
+  author: crowdsec
+  severity: info
+  description: CVE-2026-73570 testing
+  tags: appsec-testing
+http:
+  - raw:
+      - |
+        POST / HTTP/1.1
+        Host: {{Hostname}}
+        Content-Type: application/octet-stream
+        Content-Length: 123
+
+        EHLO `nslookup {{interactsh-url}}`
+        MAIL FROM:<zimbra@`nslookup {{interactsh-url}}`>
+        RCPT TO:<postmaster@localhost>
+        QUIT
+    cookie-reuse: true
+    matchers:
+      - type: status
+        status:
+          - 403

.appsec-tests/vpatch-CVE-2026-73570/config.yaml

@@ -0,0 +1,5 @@
+## autogenerated on 2026-09-17 09:30:13
+appsec-rules:
+  - ./appsec-rules/crowdsecurity/base-config.yaml
+  - ./appsec-rules/crowdsecurity/vpatch-CVE-2026-73570.yaml
+nuclei_template: CVE-2026-73570.yaml

appsec-rules/crowdsecurity/vpatch-CVE-2026-73570.yaml

@@ -0,0 +1,31 @@
+## autogenerated on 2026-09-17 09:30:13
+name: crowdsecurity/vpatch-CVE-2026-73570
+description: 'Detects Zimbra Collaboration Suite SMTP command injection using shell command substitution in SMTP commands.'
+rules:
+  - and:
+      - zones:
+          - RAW_BODY
+        transform:
+          - lowercase
+        match:
+          type: contains
+          value: 'ehlo `'
+      - zones:
+          - RAW_BODY
+        transform:
+          - lowercase
+        match:
+          type: contains
+          value: 'nslookup '
+
+labels:
+  type: exploit
+  service: http
+  confidence: 3
+  spoofable: 0
+  behavior: 'http:exploit'
+  label: 'Zimbra Collaboration Suite - RCE'
+  classification:
+    - cve.CVE-2026-73570
+    - attack.T1059
+    - cwe.CWE-78

collections/crowdsecurity/appsec-virtual-patching.yaml

@@ -71,6 +71,7 @@ appsec-rules:
 - crowdsecurity/vpatch-CVE-2018-13379
 - crowdsecurity/vpatch-CVE-2022-26134
 - crowdsecurity/vpatch-CVE-2026-1557
+- crowdsecurity/vpatch-CVE-2026-73570
 - crowdsecurity/vpatch-CVE-2024-34102
 - crowdsecurity/vpatch-CVE-2024-29973
 - crowdsecurity/vpatch-CVE-2022-41082