CVE-2019-19781
An issue was discovered in Citrix Application Delivery Controller (ADC) and Gateway 10.5, 11.1, 12.0, 12.1, and 13.0. They allow Directory Traversal.
- CVSS
- 9.8Criticalscored by CISA
- Exploited in the wild
- Yes, in CISA KEV since 3 Nov 2021CISA deadline for US federal agencies: 3 May 2022known use in ransomware campaignspublic exploit code
- EPSS
- > 99.9%chance of exploitation in the next 30 daystop 0.1% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 27 Dec 2019analysed here 12 Nov 2026
Do first. Apply updates per vendor instructions. (CISA's required action for this KEV entry)
Summary
Triage
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
Products named in our analysis
- citrix:application_delivery_controller_firmware
- citrix:netscaler_gateway_firmware
- citrix:gateway_firmware
Fix and mitigation
WAF and other mitigations
Can a WAF block it? Yes. Path traversal sends `../` sequences in the request, which WAF rules catch, including the common encodings. Azure WAF also publishes a rule written for this CVE.
Azure WAF · 1 rule
- 99001002 · Critical - 5
Also consider: canonical path validation
Based on WAF vendor rules published for this CVE. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Listed since 3 Nov 2021. Known use in ransomware campaigns.
- CISA due date
- 3 May 2022, the remediation deadline for US federal agencies
- CISA required action
- Apply updates per vendor instructions.
- Public exploit code
- Yes: 3 on Exploit-DB · 2 Metasploit modules · 44 GitHub proofs of concept · 1 Nuclei template
- CISA SSVC
- exploitation active, automatable yes, technical impact totalAssessed by CISA 8 Jan 2020 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.
Exploit-DB
- Citrix Application Delivery Controller (ADC) and Gateway 13.0 - Path Traversalwebapps, 16 Jan 2020
- Citrix Application Delivery Controller and Gateway 10.5 - Remote Code Execution (Metasploit)webapps, 13 Jan 2020
- Citrix Application Delivery Controller and Citrix Gateway - Remote Code Execution (PoC)webapps, 11 Jan 2020
Metasploit
- exploit/freebsd/http/citrix_dir_traversal_rceexploit, rank excellent
- auxiliary/scanner/http/citrix_dir_traversalauxiliary, rank normal
Nuclei
- Citrix ADC and Gateway - Directory Traversaldetection template, critical
GitHub proofs of concept
- trustedsec/cve-2019-19781573 stars
- projectzeroindia/CVE-2019-19781369 stars
- mpgn/CVE-2019-19781157 stars
- MalwareTech/CitrixHoneypot120 stars
and 40 more repositories
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
Timeline
- 27 Dec 2019Published
- 8 Jan 2020CISA SSVC assessment: exploitation active11 days later
- 10 Jan 2020First public exploit or proof of concept2 days later
- 3 Nov 2021Added to CISA KEV (exploited in the wild)663 days (about 2 years) later
- 3 May 2022CISA remediation due date (US federal agencies)181 days (about 6 months) later
- 12 Aug 2026CVE record last updated1,562 days (about 4 years) later
- 12 Nov 2026Analysed by vulneraibility.com92 days (about 3 months) later
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
| Metric | Value | What it means |
|---|---|---|
| Attack vector | NetworkReachable over the internet or any routable network. | Reachable over the internet or any routable network. |
| Attack complexity | LowRepeatable attack, no special conditions. | Repeatable attack, no special conditions. |
| Privileges required | NoneThe attacker needs no prior access. | The attacker needs no prior access. |
| User interaction | NoneNo victim action needed. | No victim action needed. |
| Scope | UnchangedImpact stays within the vulnerable component. | Impact stays within the vulnerable component. |
| Confidentiality | HighTotal data disclosure possible. | Total data disclosure possible. |
| Integrity | HighComplete modification possible. | Complete modification possible. |
| Availability | HighFull outage possible. | Full outage possible. |
Common questions
Is CVE-2019-19781 being exploited?
Yes. CVE-2019-19781 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2019-19781?
CVE-2019-19781 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2019-19781?
Yes. A fix has been recorded for CVE-2019-19781. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2019-19781 affect?
CVE-2019-19781 affects citrix:application_delivery_controller_firmware, citrix:netscaler_gateway_firmware, citrix:gateway_firmware. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
11 references in the CVE record, grouped by the tags the record gives them.
Advisories (1)
- kb.cert.org /vuls/id/619785
Other links (10)
- support.citrix.com /article/CTX267027
- twitter.com /bad_packets/status/1215431625766424576
- badpackets.net /over-25000-citrix-netscaler-endpoints-vulnerable-to-cve-2019-19781/
- forms.gle /eDf3DXZAv96oosfj6
- packetstormsecurity.com /files/155904/Citrix-Application-Delivery-Controller-Gateway-Remote-Code-Executi
- packetstormsecurity.com /files/155930/Citrix-Application-Delivery-Controller-Gateway-10.5-Remote-Code-Ex
Show 4 more
- packetstormsecurity.com /files/155905/Citrix-Application-Delivery-Controller-Gateway-Remote-Code-Executi
- packetstormsecurity.com /files/155947/Citrix-ADC-NetScaler-Directory-Traversal-Remote-Code-Execution.htm
- packetstormsecurity.com /files/155972/Citrix-ADC-Gateway-Path-Traversal.html
- cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-19781
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Exploit-DB: published exploits
- Metasploit Framework: exploit and scanner modules
- Nuclei templates: detection templates
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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