CVE-2019-6293 Denial of service in n/a
Remote attackers can cause a denial of service in the Flex lexical analyzer library via stack exhaustion triggered by specific input patterns.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2019-6293?
CVE-2019-6293 is a medium-severity denial of service vulnerability in n/a, published on 15 Jan 2019. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
An issue was discovered in the function mark_beginning_as_normal in nfa.c in flex 2.6.4. There is a stack exhaustion problem caused by the mark_beginning_as_normal function making recursive calls to itself in certain scenarios involving lots of '*' characters. Remote attackers could leverage this vulnerability to cause a denial-of-service.
Weakness: CWE-674
Which versions are affected by CVE-2019-6293?
It affects 1 product.
Products include Westes Flex.
How do I fix CVE-2019-6293?
Upgrade to a fixed version.
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-2019-6293 being exploited?
There is no known exploitation of CVE-2019-6293 in the wild and no public exploit code.
Other vulnerabilities in n/a
Sources
Also known as AZL-40794, AZL-6424, DEBIAN-CVE-2019-6293, GHSA-grpp-mcmx-p7pc, JLSEC-2026-1293, UBUNTU-CVE-2019-6293.