python-ldap before 3.4.0 is vulnerable to a denial of service when ldap.schema is used for untrusted schema definitions, because of a regular expression denial of service (ReDoS) flaw in the LDAP schema parser. By sending crafted regex input, a remote authenticated attacker could exploit this vulnerability to cause a denial of service condition.
Weakness
The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Python-ldap | Python-ldap | * | 3.4.0 (excluding) |
| Python-ldap | Ubuntu | bionic | * |
| Python-ldap | Ubuntu | esm-infra/bionic | * |
| Python-ldap | Ubuntu | esm-infra/focal | * |
| Python-ldap | Ubuntu | focal | * |
| Python-ldap | Ubuntu | impish | * |
| Python-ldap | Ubuntu | jammy | * |
| Python-ldap | Ubuntu | upstream | * |
Extended Description
Attackers can create crafted inputs that
intentionally cause the regular expression to use
excessive backtracking in a way that causes the CPU
consumption to spike.