TinApplication · Debian
CVE-2017-17520
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 · uneditedtools/url_handler.pl in TIN 2.4.1 does not validate strings before launching the program specified by the BROWSER environment variable, which might allow remote attackers to conduct argument-injection attacks via a crafted URL. NOTE: a third party has reported that this is intentional behavior, because the documentation states "url_handler.pl was designed to work together with tin which only issues shell escaped absolute URLs.
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 · moderate confidenceThe url_handler.pl script in TIN 2.4.1 passes URLs directly to the program specified in the BROWSER environment variable without validation, allowing remote attackers to inject arbitrary arguments via crafted URLs. This argument injection occurs because the script does not sanitize URL input before executing the browser command.
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
TinApplication
= 2.4.1CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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 checksWork through these to decide whether this CVE applies to you.
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Check if TIN is installed and get versionRun 'dpkg -l tin' on Debian systems or 'tin -v' to see the installed versionAffected if The installed version is 2.4.1
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Locate the url_handler.pl scriptSearch for url_handler.pl in typical TIN paths such as /usr/lib/tin/ or /usr/share/tin/ using 'find /usr -name url_handler.pl 2>/dev/null'Affected if The script exists in the TIN installation directory
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Verify BROWSER environment variable is setRun 'echo $BROWSER' to see if a browser command is configuredAffected if BROWSER is set to a program that will be invoked by url_handler.pl
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Examine url_handler.pl for URL validationRead the url_handler.pl file and look for input validation logic around lines where $BROWSER or system() calls are usedAffected if The script passes URL parameters directly to the BROWSER command without sanitization or quoting
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Test if arbitrary arguments can be injectedAttempt to invoke url_handler.pl with a crafted URL containing extra arguments (e.g., '--help' appended to a URL) and observe if the arguments are executedAffected if The extra arguments are passed through and executed by the browser program
You are affected if you have TIN version 2.4.1 installed, the url_handler.pl script exists, and the BROWSER environment variable is set, allowing unvalidated URLs to inject arguments into the browser command.
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 dataImplement strict input validation to ensure only well-formed absolute URLs are processed, and use exec-like functions that avoid shell interpretation rather than passing unsanitized input to system calls.
Fix this in Tin
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-17520 — 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-2017-17520 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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