Description
The Debian shadow package before 1:4.5-1 for Shadow incorrectly lists pts/0 and pts/1 as physical terminals in /etc/securetty. This allows local users to login as password-less users even if they are connected by non-physical means such as SSH (hence bypassing PAM's nullok_secure configuration). This notably affects environments such as virtual machines automatically generated with a default blank root password, allowing all local users to escalate privileges.
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 | shadow | 1:4.5-1 | — |
| Debian 13 | shadow | 1:4.5-1 | — |
| Debian 12 | shadow | 1:4.5-1 | — |
| Debian 9 | shadow | 1:4.4-4.1+deb9u1 | DLA-2596-1 |
Advisories 1
- DLA-2596-1 shadow - security update Debian Security (DSA / DLA) · Mar 9, 2026