CVE-2023-6549 Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow
Unauthenticated attackers can cause denial of service and read out-of-bounds memory in NetScaler ADC and Gateway.
- Exploited in the wild
- Since 17 Jan 2024
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2023-6549?
CVE-2023-6549 is a high-severity memory corruption vulnerability in Cloud Software Group NetScaler ADC, published on 17 Jan 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Improper Restriction of Operations within the Bounds of a Memory Buffer in NetScaler ADC and NetScaler Gateway allows Unauthenticated Denial of Service and Out-Of-Bounds Memory Read
Weakness: CWE-119
Which versions are affected by CVE-2023-6549?
It affects 2 products.
Products include Citrix NetScaler ADC, Citrix Netscaler Gateway.
How do I fix CVE-2023-6549?
No fix has been published for CVE-2023-6549 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 7 Feb 2024.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2023-6549 being exploited?
Yes. Attackers have exploited CVE-2023-6549 in the wild since at least 17 Jan 2024.
Public exploit code: 1 Nuclei template.
Other vulnerabilities in Cloud Software Group NetScaler ADC
- CVE-2023-3519 Citrix NetScaler ADC and NetScaler Gateway Code Injection
- CVE-2026-88771 Citrix NetScaler Improper Input Validation
- CVE-2026-88772 Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer
- CVE-2023-4966 Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow
- CVE-2026-19490 Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel
Sources
Also known as GHSA-8fxh-p33g-qf5m.