dbcve.org
PostgreSQLDatabase / datastore

CVE-2017-12172

MEDIUM · 6.7 CVSS v3.0 Published 2017-11-22
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
69/100
Remediation priority · Elevated
Zero-click

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 · unedited
PostgreSQL 10.x before 10.1, 9.6.x before 9.6.6, 9.5.x before 9.5.10, 9.4.x before 9.4.15, 9.3.x before 9.3.20, and 9.2.x before 9.2.24 runs under a non-root operating system account, and database superusers have effective ability to run arbitrary code under that system account. PostgreSQL provides a script for starting the database server during system boot. Packages of PostgreSQL for many operating systems provide their own, packager-authored startup implementations. Several implementations use a log file name that the database superuser can replace with a symbolic link. As root, they open(), chmod() and/or chown() this log file name. This often suffices for the database superuser to escalate to root privileges when root starts the server.

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 confidence

PostgreSQL startup scripts run as root and perform chmod()/chown() operations on log files. A database superuser (like the postgres user) can replace the log file with a symbolic link to an arbitrary system file, causing the root-level script to modify permissions/ownership of that file. This allows the postgres user to escalate to root privileges.

MitigationReplace or modify PostgreSQL startup scripts to not follow symbolic links for log files owned by the database superuser, or ensure the script validates log file paths before performing privileged operations. Upgrade to PostgreSQL 10.1, 9.6.6, 9.5.10, 9.4.15, 9.3.20, or 9.2.24 or later.

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
PostgreSQLDatabase / datastore
Affected:= 9.2= 9.2.1= 9.2.2= 9.2.3= 9.2.4= 9.2.5= 9.2.6= 9.2.7= 9.2.8= 9.2.9= 9.2.10= 9.2.11

CVSS 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
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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 checks

Work through these to decide whether this CVE applies to you.

  1. Check installed PostgreSQL version
    Run 'psql --version' or 'rpm -q postgresql-server' or 'dpkg -l postgresql' to determine the installed PostgreSQL version number
    Affected if Version is 9.2.x (9.2 through 9.2.11 inclusive)
  2. Verify PostgreSQL service account exists
    Check for 'postgres' user with 'id postgres' or 'getent passwd postgres'
    Affected if The postgres superuser account exists on the system
  3. Locate PostgreSQL log file configuration
    Inspect postgresql.conf for 'log_directory' and 'log_filename' settings, or check default locations /var/lib/pgsql/data/pg_log or /var/log/postgresql
    Affected if Log files are stored in a directory writable by the postgres user
  4. Check log file permissions and ownership
    Run 'ls -la' on the PostgreSQL log directory and examine if the postgres user owns or can write to log files
    Affected if The postgres user can replace log files with symbolic links
  5. Identify startup scripts that handle log files
    Look for scripts in /etc/init.d/postgresql, /usr/libexec/postgresql, or systemd service files that perform chmod/chown on log files
    Affected if Startup scripts perform privileged chmod/chown operations on log files without validating symbolic links

System is affected if PostgreSQL version 9.2.0-9.2.11 is installed, the postgres user can replace log files with symbolic links, and startup scripts run as root to chmod/chown those log files.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Replace or modify PostgreSQL startup scripts to not follow symbolic links for log files owned by the database superuser, or ensure the script validates log file paths before performing privileged operations. Upgrade to PostgreSQL 10.1, 9.6.6, 9.5.10, 9.4.15, 9.3.20, or 9.2.24 or later.

Fix this in PostgreSQL Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2017-12172 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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