Kevin BeaumontIf you like China goes brr and cyber willy waves, today will be a good day
Three new CVEs for Cisco AnyConnect/ASA
CVE-2025-20333
CVE-2025-20363
CVE-2025-20362
Chained and under active exploitation since earlier in the year
These are really important to patch btw, it's unauth RCE in Cisco AnyConnect/ASA and yes - zero day, despite the wording. China goes brrr, expect the interweb to get plastered with details soon. #CyberWillyWave
To find your org on .@shodan search for:
"acSamlv2Error=" "webvpnc=" "Cache-Control: no-store"
Then add org:YourOrg or ssl:YourOrg
And yes, @greynoise caught #CyberWillyWave as soon as it started. https://www.greynoise.io/blog/scanning-surge-cisco-asa-devices
25,000 IPs Scanned Cisco ASA Devices — New Vulnerability Potentially Incoming
GreyNoise observed two scanning surges against Cisco Adaptive Security Appliance (ASA) devices in late August including more than 25,000 unique IPs in a single burst. This activity represents a significant elevation above baseline, typically registering at less than 500 IPs per day.
Fixed versions, get to the ones highlighted in yellow ASAP as china goes double brr now
If you're on an unsupported ASA release you want to put it in the bin. If it didn't have secure boot, woops.
If anybody knows anybody at CISA, they have wrong/non-existent CVE on their executive order thingy, it's a typo that needs fixing. Edit: fixed.
With the Cisco blog, it reads like there is no problem.. but like, RCE vuln is RCE and still a problem.
Just because secure boot works (yay btw) doesn't mean there's no problem - of course they'll be no evidence on the box.
Interestingly, although the Cisco blog says the USG approached them in May 2025, the first vuln - CVE-2025-20333 - was fixed just over a year ago (around September 2024 product updates).
Another angle to that - it suggests a whole lot of orgs don't patch Cisco ASA edge devices. Which we already know from the Akira ransomware incidents -- which were using 5 year old vulns.
Just remembered I hashtagged all this #CyberWillyWave. One way to avoid being quoted in the media, unlocked!
I've identified a way to establish if a box is vulnerable to #CyberWillyWave and started internet scanning, 90k boxes in progress.
Results probably at weekend if I'm bored or early next week.
Spoiler: a lot of orgs don't patch their Cisco edge devices. To be vuln to the full chain you have to be over a year behind with updates... and most orgs are over a year behind.
From #CyberWillyWave scanning at weekend:
45210 ASAs with WebVPN enabled
1250 ASAs patched for all three CVEs
43960 vulnerable ASAs remaining
97.24% remain vulnerable
Scans rerunning
The good news with that one btw is it's unlikely to become a thing e-crime groups exploit as it's too technically complex, it's just nation state espionage - so the operational impact should be low.
The bad news is that as e-crime groups become more rich, they may invest in AnyConnect exploits - if you paid something like $2m for an ASA exploit, you'd make it back no problem, even if an n-day as almost nobody patches.
*.gov.uk is less than 1% patched btw, many of the systems haven't been patched for years - the dates are firmware versions. The US federal government is only marginally better. I'm guessing orgs don't even know where they have ASA.
The plan is to start publishing the data publicly since I don't think anybody has an understanding of what the real world looks like.
I had to restart the #CyberWillyWave ASA scan as my server restarted (RIP), but it looks a bit better today - approx. 10% patched now, 5 days in.
My Cisco ASA firmware versions scan is now public: https://github.com/GossiTheDog/scanning/blob/main/Cisco-ASA-firmware-updates-CVE-2025-20333-CVE-2025-20363-CVE-2025-20362.csv
Fields:
IP,hostnames,FirmwareVersionKnown,FirmwareModifiedDate,Errors
Dates are UK date format - DD/MM/YY
If FirmwareModifiedDate is below */08/25 or */09/25, the device is vulnerable to #CyberWillyWave as the firmware was complied August 2025 or later.
New scan running now, results at weekend.
It gives you a very good indication as to how regularly orgs patch, e.g.
Gotta make sure we buy magic boxes to defend against AI GenV cyber mega attacks and quantum
My Cisco ASA firmware versions scan is now updated: https://github.com/GossiTheDog/scanning/blob/main/Cisco-ASA-firmware-updates-CVE-2025-20333-CVE-2025-20363-CVE-2025-20362.csv
Fields:
IP,hostnames,FirmwareVersionKnown,FirmwareModifiedDate,Errors
Dates are UK date format - DD/MM/YY
If FirmwareModifiedDate is below */08/25 or */09/25, the device is vulnerable to #CyberWillyWave as the fixed firmware was complied August 2025 or later.
New scan running now, results at midweek.
Patch rates are still below 20%.
Edit: #CyberWillyWave
My Cisco ASA firmware versions scan is now updated: https://github.com/GossiTheDog/scanning/blob/main/Cisco-ASA-firmware-updates-CVE-2025-20333-CVE-2025-20363-CVE-2025-20362.csv
Fields:
IP,hostnames,FirmwareVersionKnown,FirmwareModifiedDate,Errors
Dates are UK date format - DD/MM/YY
If FirmwareModifiedDate is below */08/25 or */09/25, the device is vulnerable to #CyberWillyWave as the fixed firmware was complied August 2025 or later.
New scan running now, results at weekend.
Patch rates are at 22% complete, two weeks in.
Y'all probably want to patch.
If anybody is wondering, number of Cisco ASA devices with WebVPN enabled with their firmware year:
2025 - 10570
2024 - 12428
2023 - 3888
2022 - 4594
2021 - 3951
2020 - 2076
The average is orgs are around 18 months behind with patching (for internet facing).
If anybody is wondering how these scans are generated - one time @shodan search for AnyConnect boxes, export, then vibe coded scanner that fingerprints firmware creation date using the SSL applet and outputs to CSV.
About 40% of orgs are missing from results as they are clientless.
There’s much better ways of doing it.
Those Cisco ASA vulns continue to be patched at a slow rate.
UK orgs, sign up for the NCSC Early Warning system and actually patch your systems when notified.
https://www.ncsc.gov.uk/section/active-cyber-defence/early-warning
scott@GossiTheDog please know the security team is desperately trying to get the infrastructure team to patch D: