Ubuntu LinuxOperating system · Canonical
CVE-2021-32550
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 · uneditedIt was discovered that read_file() in apport/hookutils.py would follow symbolic links or open FIFOs. When this function is used by the openjdk-14 package apport hooks, it could expose private data to other local users.
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 confidenceThe read_file() function in apport/hookutils.py follows symbolic links and opens FIFOs (named pipes) without validation. When used by openjdk-14 package apport hooks, this allows local unprivileged users to potentially read sensitive files via symlink traversal or access data from FIFOs they control, exposing private information.
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
Ubuntu LinuxOperating system
= 18.04= 20.04= 20.10= 21.04= 21.10CVSS 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:3.1/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 if apport is installedRun `dpkg -l apport` or `apt list --installed 2>/dev/null | grep -i apport`Affected if apport is not installed, the system is not affected by this specific vulnerability in apport
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Check the installed apport versionRun `dpkg -s apport | grep Version`Affected if the version matches Ubuntu 18.04, 20.04, 20.10, 21.04, or 21.10 package versions that contain the vulnerable read_file() function in hookutils.py
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Check if openjdk-14 apport hooks existLook for hooks in /usr/share/apport/package-hooks/ directory, specifically for openjdk-14: `ls /usr/share/apport/package-hooks/*.py 2>/dev/null | xargs grep -l openjdk 2>/dev/null`Affected if openjdk-14 package hooks exist that invoke the vulnerable read_file() function from hookutils.py
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Verify the read_file function lacks symlink/FIFO protectionExamine /usr/lib/python3/dist/apport/hookutils.py for the read_file() function and check if it uses O_NOFOLLOW flag or validates file types with stat checks before openingAffected if the read_file() function does not use O_NOFOLLOW or stat-based type validation, meaning it follows symlinks and opens special files like FIFOs without restriction
A system is affected if it runs an affected Ubuntu version with the vulnerable apport version that includes openjdk-14 hooks, and the read_file() function in hookutils.py lacks O_NOFOLLOW or stat validation for symlinks and special files.
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 dataModify read_file() to validate paths before opening—reject symbolic links and special file types like FIFOs—or use O_NOFOLLOW and stat checks to ensure only regular files are read.
Fix this in Ubuntu Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-32550 — 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-2021-32550 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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- Version or environment caveats, and links to real fixes
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