CVE-2017-1000383
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedGNU Emacs version 25.3.1 (and other versions most likely) ignores umask when creating a backup save file ("[ORIGINAL_FILENAME]~") resulting in files that may be world readable or otherwise accessible in ways not intended by the user running the emacs binary.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceGNU Emacs 25.3.1 and earlier versions create backup files (named with ~ suffix) without respecting the system's umask setting, resulting in files created with default permissions (typically 0644) that may be world-readable. This exposes potentially sensitive data in backup files to other users on multi-user systems.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 25.3.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed Emacs versionRun `emacs --version` or `M-x emacs-version` inside Emacs. Compare the version number to the affected range (<= 25.3.0).Affected if The installed version is 25.3.0 or earlier
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Verify backup file creation is enabledOpen Emacs and evaluate `(if (boundp 'make-backup-files) make-backup-files)` or check your init file (~/.emacs, ~/.emacs.d/init.el) for `(setq make-backup-files` statements.Affected if `make-backup-files` is not explicitly set to nil or the variable evaluates to non-nil
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Find backup files with permissive permissionsUse `find ~ -name '*~' -perm -004` or `find /path/to/project -name '*~' -perm -004` to locate backup files readable by others (mode includes o+r or is 0644).Affected if Any backup files exist with world-readable permissions (mode 0644 or with o+r bit set)
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Check backup directory permissionsIf `backup-directory-alist` is configured, inspect the target directory with `ls -la`. If not configured, check the directories where you edit files for backup files.Affected if Backup files are written to directories accessible by other users or directories lack restrictive permissions
You are affected if running Emacs version 25.3.0 or earlier, backup file creation is enabled, and backup files with world-readable permissions (~ suffix, mode 0644) exist in shared or accessible locations.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataDisable backup file creation via `(setq make-backup-files nil)` in Emacs configuration, or set `backup-directory-alist` to use a secure, permission-controlled directory, and audit existing world-readable backup files.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2017-1000383 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2017-1000383 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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