CVE-2023-3519
CRITICALCVE-2023-3519 is a critical-severity (CVSS 9.8) Code Injection vulnerability. It is in CISA's Known Exploited Vulnerabilities catalog (added 2023-07-19) and has been used in ransomware campaigns — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
Unauthenticated remote code execution
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2023-07-19 — including use in ransomware campaigns. Federal agencies were required to remediate by 2023-08-09.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2023-3519.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2023-3519 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Counts from FIRST.org, log-scaled.
Description
Unauthenticated remote code execution
Affected Products
netscaler application delivery controllercitrixnetscaler gatewaycitrixResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Unauthenticated remote code execution
Unauthenticated remote code execution
Unauthenticated remote code execution
Unauthenticated remote code execution
Unauthenticated remote code execution
Unauthenticated remote code execution
Unauthenticated remote code execution
Unauthenticated remote code execution
Unauthenticated remote code execution
Unauthenticated remote code execution
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2023-3519 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
How to detect CVE-2023-3519
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2023-3519 -u https://target- Template
- Citrix NetScaler ADC and NetScaler Gateway - Remote Code Execution
- Severity
- critical
- Impact
- Unauthenticated attackers can exploit SAML processing vulnerabilities to execute arbitrary code on Citrix ADC and Gateway appliances, potentially compromising corporate network access and intercepting VPN traffic.
- Remediation
- Apply Citrix security patches as outlined in CTX561482 to fix the SAML processing vulnerability in NetScaler ADC and Gateway appliances.
Template by ProjectDiscovery nuclei-templates (pussycat0x, ritikchaddha), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2023-3519 in your dependencies?
Find it across , including transitive dependencies.