CVE intelligence and bounded remediation
CVE-2021-23240 — Sudo Project Sudo security vulnerability
selinux_edit_copy_tfiles in sudoedit in Sudo before 1.9.5 allows a local unprivileged user to gain file ownership and escalate privileges by replacing a temporary file with a symlink to an arbitrary file target. This affects SELinux RBAC support in permissive mode. Machines without SELinux are not vulnerable.
- Severity
- High
- CVSS
- 7.8 (3.1)
- Published
- 2021-01-12
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-59
Affected products
- sudo_project / sudo
- netapp / hci_management_node
- netapp / solidfire
- fedoraproject / fedora / 32
- fedoraproject / fedora / 33
Showing 5 representative product identities from 6 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.
Matched remediation archetype
Path traversal, unsafe upload, and file handling
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
- Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
- Review canonicalization and containment checks across supported operating systems and storage backends.
Remediate safely
- Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
- Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
- Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.
Authoritative sources
Complete CVE record and remediation plan
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