Description
An issue was discovered in LemonLDAP::NG before 2.16.1. Weak session ID generation in the AuthBasic handler and incorrect failure handling during a password check allow attackers to bypass 2FA verification. Any plugin that tries to deny session creation after the store step does not deny an AuthBasic session.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | lemonldap-ng | 2.16.1+ds-1 | — |
| Debian 13 | lemonldap-ng | 2.16.1+ds-1 | — |
| Debian 12 | lemonldap-ng | 2.16.1+ds-1 | — |
| Debian 10 | lemonldap-ng | 2.0.2+ds-7+deb10u9 | DLA-3496-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | lemonldap-ng | No fix yet | — |
| Ubuntu 22.04 LTS | lemonldap-ng | No fix yet | — |
| Ubuntu 20.04 LTS | lemonldap-ng | No fix yet | — |
| Ubuntu 18.04 LTS | lemonldap-ng | No fix yet | — |
| Ubuntu 16.04 LTS | lemonldap-ng | No fix yet | — |
Advisories 1
- DLA-3496-1 lemonldap-ng - security update Debian Security (DSA / DLA) · Mar 9, 2026