CVE-2018-20809 Denial of service in n/a
A crafted message can crash the Pulse Secure Pulse Connect Secure web server, causing a denial of service for administrators and users.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2018-20809?
CVE-2018-20809 is a high-severity denial of service vulnerability in Ivanti Connect Secure, published on 16 Mar 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A crafted message can cause the web server to crash with Pulse Secure Pulse Connect Secure (PCS) 8.3RX before 8.3R5 and Pulse Policy Secure 5.4RX before 5.4R5. This is not applicable to PCS 8.1RX.
Weakness: CWE-20
Which versions are affected by CVE-2018-20809?
It affects 2 products.
Products include Ivanti Connect Secure, Pulsesecure Pulse Policy Secure.
How do I fix CVE-2018-20809?
No fix has been published for CVE-2018-20809 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2018-20809 being exploited?
There is no known exploitation of CVE-2018-20809 in the wild and no public exploit code.
Other vulnerabilities in Ivanti Connect Secure
- CVE-2021-22893 Ivanti Pulse Connect Secure Use-After-Free
- CVE-2019-11510 Ivanti Pulse Connect Secure Arbitrary File Read
- CVE-2024-21887 Ivanti Connect Secure and Policy Secure Command Injection
- CVE-2025-22457 Ivanti Connect Secure, Policy Secure, and ZTA Gateways Stack-Based Buffer Overflow
- CVE-2025-0282 Ivanti Connect Secure, Policy Secure, and ZTA Gateways Stack-Based Buffer Overflow
Sources
Also known as GHSA-x2mw-2wgh-5r92.