CrossroadsApplication · Debian
CVE-2018-18654
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 · uneditedCrossroads 2.81 does not properly handle the /tmp directory during a build of xr. A local attacker can first create a world-writable subdirectory in a certain location under the /tmp directory, wait until a user process copies xr there, and then replace the entire contents of this subdirectory to include a Trojan horse xr.
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 confidenceCrossroads 2.81 has a race condition vulnerability where the xr tool is copied to a location under /tmp during the build process without proper safeguards. A local attacker can pre-create a world-writable subdirectory in the target /tmp path, wait for a user to build xr, then replace the binary with a Trojan horse version before the copy completes.
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
CrossroadsApplication
= 2.81CVSS 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
- High
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:L/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 checksWork through these to decide whether this CVE applies to you.
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Check installed Crossroads versionRun 'dpkg -l crossroads' or 'apt list --installed 2>/dev/null | grep crossroads' to see if Crossroads version 2.81 is installedAffected if Version shown is exactly 2.81 (only this version is affected)
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Locate the xr binaryRun 'which xr' or 'find /usr -name xr 2>/dev/null' to find the xr binary locationAffected if The xr binary exists on the system and was built from version 2.81
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Check for world-writable subdirectories in /tmpRun 'ls -la /tmp/' and look for unexpectedly world-writable subdirectories (drwxrwxrwx permissions) that may have been pre-created by an attackerAffected if World-writable directories exist in /tmp that could be used to exploit the race condition during build
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Verify xr binary integrityRun 'ls -la <path_to_xr>' to check file permissions and ownership. Compare file hash if you have a known-good baseline: 'sha256sum <path_to_xr>'Affected if The binary has unexpected permissions, ownership, or hash differs from expected (indicating potential Trojan horse replacement)
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Review build process historyCheck build logs or shell history for how xr was built. Look for whether /tmp was used as a temporary directory during the buildAffected if The build process used /tmp without secure safeguards like mktemp or a private build directory
You are affected if Crossroads version 2.81 is installed or was built, AND the build process used an insecure /tmp location, AND there are indicators of compromise such as unexpected world-writable /tmp subdirectories or a tampered xr binary.
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 dataEnsure the build process uses a secure, private temporary directory (e.g., via mktemp or a dedicated build directory) rather than a shared /tmp location, and verify binary integrity after building.
Fix this in Crossroads
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 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 $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-18654 — 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-2018-18654 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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