What is 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.
The record classifies CVE-2019-19781 under weakness class CWE-22. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 13 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 2499 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS (FIRST)
- 99.9% probability of exploitation in the next 30 days, higher than 99.9% of all scored CVEs
- CISA KEV
- Listed since 2021-11-03, federal remediation deadline 2022-05-03 — used in known ransomware campaigns
- Threadlinqs priority
- 10/10 — CISA lists it as used in ransomware, which Threadlinqs scores at the maximum
- Published
- 2019-12-27, last modified 2026-08-12
Is CVE-2019-19781 being exploited?
CISA added CVE-2019-19781 to the Known Exploited Vulnerabilities catalog on 2021-11-03, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2022-05-03 under BOD 22-01. CISA flags the vulnerability as one used in known ransomware campaigns. Weaponised exploit code for CVE-2019-19781 is publicly available. 11 public proof-of-concept repositories are tracked for this identifier. A ProjectDiscovery Nuclei detection template exists (http/cves/2019/CVE-2019-19781.yaml). It currently carries a trending score of 55 in the Threadlinqs vulnerability feed.
- trustedsec/cve-2019-19781 (github)
- projectzeroindia/CVE-2019-19781 (github)
- mpgn/CVE-2019-19781 (github)
- MalwareTech/CitrixHoneypot (github)
- cisagov/check-cve-2019-19781 (github)
- mandiant/ioc-scanner-CVE-2019-19781 (github)
- jas502n/CVE-2019-19781 (github)
- citrix/ioc-scanner-CVE-2019-19781 (github)
Affected products and versions
- Citrix: Application Delivery Controller Firmware 10.5, Application Delivery Controller Firmware 11.1, Application Delivery Controller Firmware 12.0, Application Delivery Controller Firmware 12.1, Application Delivery Controller Firmware 13.0, Application Delivery Controller, Netscaler Gateway Firmware 10.5, Netscaler Gateway Firmware 11.1, Netscaler Gateway Firmware 12.0, Netscaler Gateway Firmware 12.1, Netscaler Gateway, Gateway Firmware 13.0, Gateway
How to fix CVE-2019-19781
The record marks a vendor fix as available for CVE-2019-19781. Patch reference: https://support.citrix.com/article/CTX267027. Vendor advisory: https://support.citrix.com/article/CTX267027. Because CVE-2019-19781 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2022-05-03. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2019-19781
4 tracked threats in the Threadlinqs corpus reference CVE-2019-19781, either in the campaign’s CVE list or as an indicator on the campaign record.
- Sen. Wyden Urges Binding Federal Mandate to Purge Internet-Facing Legacy VPNs for Zero-Trust Remote Access — MEDIUM · 2026-07-27
- APT41/Silver Dragon Expanding Enterprise Attack Surface — Google Drive C2, AppDomain Hijacking, Cloud/Supply Chain Targeting — HIGH · 2026-03-27
- Static Tundra ICS Attacks on Polish Energy Infrastructure with DynoWiper — CRITICAL · 2026-02-02
- Static Tundra (Dragonfly/Energetic Bear) ICS Attacks on Polish Energy Infrastructure — CRITICAL · 2026-02-02
Sources
Enriched from CVE.org, NVD, FIRST EPSS, CISA KEV, public proof-of-concept repositories, ProjectDiscovery Nuclei. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.
Vendor advisory and patch
Third-party advisory
Other references
- twitter.com
- badpackets.net
- forms.gle
- packetstormsecurity.com
- packetstormsecurity.com (Citrix Application Delivery Controller G)
Showing 7 of 10 recorded references.