Updated CitrixBleed 2 scan results: https://github.com/GossiTheDog/scanning/blob/main/CVE-2025-5777-CitrixBleed2-ElectricBoogaloo-patching.txt
It's down from 24% unpatched to 17% unpatched
The results are partial still, the actual numbers still vuln will be higher.
Imperva WAF have added detection and blocking for CitrixBleed 2 this weekend.
They see it being widely sprayed across the internet today - almost 12 million requests, log4shell level.
The only major vendor I’ve seen who hasn’t added a WAF rule is Citrix - they sell a WAF upsell module for Netscaler, but failed to add detection for their own vulnerability.
Updated Citrix scan results will go on Github in a few days, I've found a bug in the scan results setup which should add ~33% more hosts when fixed.
Spoiler:
CitrixBleed 2 update.
- Citrix have finally, quietly admitted exploitation in the wild -- by not commenting to press and then editing an old blog post and not mentioning it on their security update page.
- Orgs have been under attack from threat actors in Russia and China since June
- It's now under spray and pray, wide exploitation attempts.
https://doublepulsar.com/citrixbleed-2-situation-update-everybody-already-got-owned-503c6d06da9f
Citrix Netscaler internet scan still running, it's found another 1k vulnerable instances so far - will probably update Github later today or tomorrow morning.
It looks like we're back up to 18% of boxes being still vulnerable when the new list is out. It looks like a lot of orgs are patching from my list.
New CitrixBleed 2 scan data:
https://raw.githubusercontent.com/GossiTheDog/scanning/refs/heads/main/CVE-2025-5777-CitrixBleed2-ElectricBoogaloo-patching.txt
+7000 extra hosts added this round, host list is so large you need to use the raw view to see it.
Next set of data publication likely Friday, a month since the patch became available.
3832 orgs/hosts still unpatched.
GreyNoise blog just out about #CitrixBleed2, they see exploitation from IPs in China from June 23rd targeting specifically Netscaler appliances https://www.greynoise.io/blog/exploitation-citrixbleed-2-cve-2025-5777-before-public-poc
I’m fairly certain the threat actor is Chinese and they reversed the patch to make the exploit.
Citrix continue to be MIA. They still have no detection guidance for customers, and haven’t told customers the extent of the issue.
#CitrixBleed2
With the #CitrixBleed2 patch data I publish it's possible to view the history on Github for each new scan and see when hosts change from vuln to patched.
It's proving incredibly effective at getting orgs to patch. I tried private notifications via HackerOne and such for CitixBleed1 in 2023 and it took months to get orgs to patch. Putting the data public brings accountability for orgs who later get breached - so there's a rush to patch.
It's definitely interesting and may need a scale out.
Citrix have a blog out about hunting for #CitrixBleed2
https://www.netscaler.com/blog/news/evaluating-netscaler-logs-for-indicators-of-attempted-exploitation-of-cve-2025-5777/
It's what was in my earlier blog - look for invalid characters in the username field and duplicate sessions with different IPs
we gettin' there!
This bit is still incomplete in the patching instructions btw - if it's a HA pair you need to additionally reset other session types or you're still vulnerable to session hijack after patching.
I'm still trying to get Citrix to update the instructions.
The Dutch Public Prosecution Office have shut down their Citrix Netscaler and removed all internet access, Dutch media speculating CitrixBleed 2 exploitation.
https://www.techzine.eu/news/security/133163/dutch-department-of-justice-offline-after-citrix-vulnerability/
Justice minister David van Weel told MPs in a briefing that it appears the weakness had been used by third parties to access the department systems.
The justice ministry said the department had applied Citrix’s recommended patches, but these failed to fully eliminate the flaw. https://www.dutchnews.nl/2025/07/prosecution-department-goes-offline-due-to-software-weakness/
Again to reiterate the point in the thread - Citrix’s patching instructions don’t include - for example - resetting AAA sessions when AAA cookies are stealable with the vulnerability. So we’re going to see orgs caught with Citrix’s pants down.
Here’s the Dutch gov letter and my translation.
Update on the situation at The Hague and the shutdown of the Dutch Public Prosecution Service internet access, NCSC Netherlands issued an update today saying all orgs should hunt for CitrixBleed 2 activity, citing my blog.
They also advise clearing all session types, not just the ones Citrix say in their security advisory.
https://advisories.ncsc.nl/advisory?id=NCSC-2025-0196
Updated #CitrixBleed2 scans https://github.com/GossiTheDog/scanning/blob/main/CVE-2025-5777-CitrixBleed2-ElectricBoogaloo-patching.txt
Fields - IP, SSL certification hostnames, Netscaler firmware, if vulnerable to CVE-2025-5777
I've had a few orgs contest that they're not vulnerable and the scan is wrong. I've assisted each org, and in each case they've been wrong - they'd patched the wrong Netscaler, the passive HA node etc.
I've been working with @shadowserver@infosec.exchange btw, their scan results for #CitrixBleed2 now show far more vulnerable systems. Their scanning is independent of mine, logic is improving, more orgs will get notifications. I'm going to try getting victims for notification across too.
I might move the Dutch Public Prosecution Service (OM) Citrix Netscaler incident out to a different thread, but the latest update an hour ago from local media is that they are still without internet and remote access, and they're working on several alternatives to continue criminal trials.
I expect we're going to see a wave of Netscaler incidents over the coming months, although how many will publicly disclose is another issue - the Dutch are culturally transparent.
https://nltimes.nl/2025/07/18/dutch-prosecutor-disconnects-internal-systems-internet-vulnerability
The Canadian government cyber centre are this weekend recommending all orgs review historic logs for #CitrixBleed2 compromise, and reset all user sessions https://www.cyber.gc.ca/en/alerts-advisories/vulnerabilities-impacting-citrix-netscaler-adc-netscaler-gateway-cve-2025-5349-cve-2025-5777-cve-2025-6543
The Dutch Public Prosecution Service (OM), which took their systems offline due to #CitrixBleed2 on Friday, are saying they will be offline for weeks. https://nos.nl/artikel/2575857 HT @moartn@tacobelllabs.net
There’s a bit more in situation at the OM on Netscaler here: https://www.volkskrant.nl/binnenland/openbaar-ministerie-mogelijk-nog-weken-afgesloten-van-internet-probeert-impact-op-rechtszaken-te-beperken~b6e19434/
The OM say they patched quickly (and my scan data backs this up - they patched around June 24th) however it appears somebody got in (or took a session cookie) before patching took place and now they’re trying to contain the situation.
The NCSC are strongly advising orgs to follow the advice on my blog re #CitrixBleed2, in hindsight I probably shouldn’t have drawn the logo in MSPaint and titled a section “China goes brrrr”.
I think this thread exposes something about the cybersecurity industry and org posture btw - it almost all runs on Windows and EDR telemetry, hence why there’s little info on this from vendors (Netscaler is closed box appliance - they’re flying blind) and why orgs aren’t seeing anything, they don’t know how without vendors.
I keep contacting orgs and they have no idea they are compromised or how to investigate.
#CitrixBleed2
The Dutch Public Prosecution Service #CitrixBleed2 incident rolls on - NRC report on an email from the Director of their IT service, where they say “It is clear that it’s a massive and dramatic incident”.
https://www.nrc.nl/nieuws/2025/07/22/digitale-werkomgeving-om-inderdaad-gehackt-onderzoek-moet-uitwijzen-welke-informatie-is-gestolen-a4901019
The Dutch Public Prosecution Service Citrix Netscaler incident is rumbling on. They are working on service recovery.
https://www.databreachtoday.com/dutch-prosecutors-recover-from-suspected-russian-hack-a-29129
#CitrixBleed2
I've updated my CitrixBleed2 scan results for the first time in two weeks (I've been on holiday).
https://raw.githubusercontent.com/GossiTheDog/scanning/refs/heads/main/CVE-2025-5777-CitrixBleed2-ElectricBoogaloo-patching.txt
2637 orgs still vuln
Kevin Beaumont