CVE intelligence and bounded remediation
CVE-2017-20002 — The Debian shadow package before 1:4.5-1 for Shadow incorrectly lists pts/0 and pts/1 as physical terminals in /etc/securetty
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.
- Severity
- High
- CVSS
- 7.8 (3.1)
- Published
- 2021-03-17
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-269
Affected products
- debian / shadow / 4.4
- debian / debian_linux / 9.0
Matched remediation archetype
Privilege escalation and unsafe privilege management
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Map service accounts, operating-system identities, roles, capabilities, impersonation, set-user transitions, and administrative helper paths.
- Determine whether untrusted users or lower-privilege processes can reach the affected transition or modify inputs it trusts.
- Review file, socket, registry, device, job, container, and cloud-role permissions used before and after privilege changes.
Remediate safely
- Apply the supported fix and redesign privileged operations as a minimal, authenticated, allowlisted interface.
- Drop privileges before processing untrusted input, verify the drop succeeds, and remove unnecessary roles, capabilities, and write permissions.
- Validate ownership and permissions at time of use and add explicit lower-to-higher privilege boundary tests.
Authoritative sources
Complete CVE record and remediation plan
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