YIKES WatchGuard Fireware OS IKEv2 out-of-bounds write (CVE-...

src/network-services-pentesting/ipsec-ike-vpn-pentesting.md

@@ -14,6 +14,8 @@ The establishment of a **security association (SA)** between two points is manag
 
 **Default port:** 500/udp
 
+Also commonly exposed: 4500/udp (NAT Traversal)
+
 ## **Discover** the service using nmap
 
 ```
@@ -117,6 +119,34 @@ Ending ike-scan 1.9: 1 hosts scanned in 84.080 seconds (0.01 hosts/sec). 1 retur
 
 This can be also achieve with nmap script _**ike-version**_
 
+### IKEv2-specific: WatchGuard Vendor ID version fingerprinting
+
+Some IKEv2 daemons include non-standard Vendor ID payloads in the IKE_SA_INIT response. WatchGuard Fireware OS encodes the appliance version/build directly inside the VID, allowing single-packet, pre-auth fingerprinting.
+
+- Transport: UDP/500 (and UDP/4500 for NAT-T)
+- Packet: IKE_SA_INIT response contains one or more Vendor ID payloads
+- WatchGuard format: 32-byte hash followed by base64 that decodes to e.g. `VN=12.11.3 BN=719894`
+
+Example raw bytes from a WatchGuard VID payload (last 12 bytes are base64):
+
+```
+00000000: bfc2 2e98 56ba 9936 11c1 1e48 a6d2 0807  ....V..6...H....
+00000010: a95b edb3 9302 6a49 e60f ac32 7bb9 601b  .[....jI...2{.`.
+00000020: 566b 3439 4d54 4975 4d54 4575 4d79 4243  Vk49MTIuMTEuMyBC
+00000030: 546a 3033 4d54 6b34 4f54 513d            Tj03MTk4OTQ=
+```
+
+Quick extraction on a shell when you have the base64 tail:
+
+```bash
+echo 'Vk49MTIuMTEuMyBCTj03MTk4OTQ=' | base64 -d
+# VN=12.11.3 BN=719894
+```
+
+Notes
+- This is not part of any IKEv2 RFC. Treat it as a vendor quirk for rapid scoping of exposed/vulnerable Fireware OS versions.
+- You only need to elicit an IKE_SA_INIT reply; no authentication is required.
+
 ## Finding the correct ID (group name)
 
 For being allowed to capture the hash you need a valid transformation supporting Aggressive mode and the correct ID (group name). You probably won't know the valid group name, so you will have to brute-force it.\
@@ -259,6 +289,27 @@ In this setup:
 
 Ensure that actual, secure values are used to replace the placeholders when configuring the VPN.
 
+## IKEv2 exploitation notes: pre-auth IDi/CERT processing bugs
+
+Modern VPN appliances often expose IKEv2 on UDP/500 (and UDP/4500 for NAT-T). A common pre-authentication attack surface is the parsing of Identification (IDi) and Certificate payloads during IKE_SA_AUTH.
+
+High-level exploitation flow when a vulnerable IKEv2 parser exists:
+- Send a valid IKE_SA_INIT to negotiate transforms and complete Diffie–Hellman.
+- Follow with IKE_SA_AUTH carrying an IDi that triggers the bug (e.g., an oversized Identification copied into a fixed-size stack buffer before certificate validation).
+- Resulting memory corruption can yield saved-register and return-address control.
+- With NX enabled but other mitigations missing (no PIE/canaries), build a ROP chain to call mprotect on a stack page and then pivot execution to injected shellcode or to a resident interpreter (e.g., /usr/bin/python3) if no /bin/sh is available.
+
+Example default transforms observed on some IKEv2 appliances (WatchGuard Fireware OS 12.11.3):
+- SHA2-256–AES(256-bit) with DH Group 14
+- SHA1–AES(256-bit) with DH Group 5
+- SHA1–AES(256-bit) with DH Group 2
+- SHA1–3DES with DH Group 2
+
+Practical tips
+- Target both UDP/500 and UDP/4500; NAT-T servers may reply only on 4500.
+- Increase receive buffer and timeouts for UDP-based scanners to avoid packet loss.
+- If the service exposes custom Vendor IDs (see section above), use them to quickly fingerprint vulnerable versions before attempting any exploit traffic.
+
 ## Reference Material
 
 - [PSK cracking paper](http://www.ernw.de/download/pskattack.pdf)
@@ -269,5 +320,11 @@ Ensure that actual, secure values are used to replace the placeholders when conf
 ## Shodan
 
 - `port:500 IKE`
+- `port:4500 "UDP"`
+- `udp port:500,4500 "WatchGuard"`
 
-{{#include ../banners/hacktricks-training.md}}
+## References
+
+- [YIKES: WatchGuard Fireware OS IKEv2 out-of-bounds write (CVE-2025-9242)](https://labs.watchtowr.com/yikes-watchguard-fireware-os-ikev2-out-of-bounds-write-cve-2025-9242/)
+
+{{#include ../banners/hacktricks-training.md}}