Hey folks! 👋 Wanted to share an experience from a recent engagement where our team performed an authorized penetration test against a web app protected by a CloudGen Firewall (specifically, the F-Series virtual appliance). The client was particularly concerned about Layer 7 attacks and wanted to see if the WAF and IPS features held up.
We ran a standard web app pen-test toolkit (Burp Suite, custom scripts) and a network-level scan. Here's a quick breakdown of what we observed:
* **WAF Rules & Signatures:** The out-of-the-box OWASP Core Rule Set (CRS) caught a lot of the low-hanging fruit—basic SQLi attempts, obvious XSS payloads—and logged them cleanly. We had to tweak our payloads significantly to evade detection for more advanced testing.
* **Performance Under Load:** We simulated a DDoS (HTTP flood) with a tool, and the rate limiting and connection limiting features kicked in effectively. The protected service stayed up, though we did notice a slight increase in latency for legitimate traffic during the peak. The logs were *very* detailed, which helped in the post-mortem.
* **A Small Gotcha:** We found that a specific, obfuscated directory traversal attempt slipped through the default profile. It highlighted the importance of tuning. The fix was adding a custom rule. The syntax for that was straightforward:
```bash
# Example of a custom URL access rule we recommended
create rule condition URL_Contains pattern "/../"
create rule action Block
```
Overall, it held up really well. The key takeaway? It's solid out of the box, but like any security tool, its strength multiplies with proper tuning to your specific environment. Has anyone else put it through its paces? I'm curious if your experiences with the ATP or sandboxing features during a test matched ours.
Happy coding (and securing)!
Clean code, happy life
Interesting data point. Your observation about the OWASP CRS catching the basics but requiring payload tweaking aligns with my own benchmark testing. The key metric we tracked was the *evasion threshold* - the number of encoding or fragmentation iterations required to bypass a signature. For the CloudGen CRS implementation, that threshold was notably higher than some cloud-native WAFs we've tested, especially for SQLi.
Regarding the performance under load, the latency increase you saw is critical. Was that measured from inside your simulated attack network, or from an external, "clean" monitoring node? In our tests, the increase often stemmed from TCP stack tuning on the virtual appliance itself under extreme connection churn, not the rules processing. Adjusting the `syn_retries` and connection table timeouts in the advanced networking profile usually brought it back in line.
I'm very curious about the obfuscated directory traversal gotcha you mentioned. In our last assessment, we found that certain UTF-8 normalization sequences could sometimes slip past the URL normalization parser before the CRS inspected it, but that was patched in a later firmware update. Was the evasion technique related to encoding, or something in the path parameter parsing logic?
—chris
Interesting. Those detailed logs are a huge plus for the post-mortem phase, but I'm always curious about the cost side of storing and processing them. Did you happen to see the volume of log data generated per hour during the peak of the DDoS simulation? I've seen similar setups where the logging overhead alone became a significant line item in the cloud bill, especially if you're shipping everything to a SIEM.
Also, on the small gotcha you mentioned slipping through, was that due to a default rule being disabled for performance reasons, or just a gap in the signature set? Knowing which one helps decide if you need a custom rule or just a policy tune-up.
Thanks for sharing the detailed rundown. I'm glad the CRS caught the expected baseline and that the logging granularity proved useful. That's a key feature for turning an event into a learning opportunity.
You mentioned a specific obfuscated directory traversal attempt slipping through. That's a common pain point. When you reviewed the logs, was the request flagged with a lower severity or was it just absent altogether? Sometimes the default paranoia level lets some more obscure encodings pass, which means you might need to bump it up a notch for that specific path.
Stay curious, stay critical.