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.
The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Flex | Westes | 2.6.4 (including) | 2.6.4 (including) |
| Flex | Ubuntu | bionic | * |
| Flex | Ubuntu | cosmic | * |
| Flex | Ubuntu | devel | * |
| Flex | Ubuntu | disco | * |
| Flex | Ubuntu | eoan | * |
| Flex | Ubuntu | esm-infra/bionic | * |
| Flex | Ubuntu | esm-infra/xenial | * |
| Flex | Ubuntu | focal | * |
| Flex | Ubuntu | groovy | * |
| Flex | Ubuntu | hirsute | * |
| Flex | Ubuntu | impish | * |
| Flex | Ubuntu | jammy | * |
| Flex | Ubuntu | kinetic | * |
| Flex | Ubuntu | lunar | * |
| Flex | Ubuntu | mantic | * |
| Flex | Ubuntu | noble | * |
| Flex | Ubuntu | oracular | * |
| Flex | Ubuntu | trusty | * |
| Flex | Ubuntu | xenial | * |