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KtorApplication · Jetbrains

CVE-2019-12737

MEDIUM · 5.3 CVSS v3.1 Published 2019-10-02
Fix available
A fix is available. Upgrade to after 1.1.5 or later.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges 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
UserHashedTableAuth in JetBrains Ktor framework before 1.2.0-rc uses a One-Way Hash with a Predictable Salt for storing user credentials.

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 confidence

The UserHashedTableAuth authentication feature in JetBrains Ktor framework versions prior to 1.2.0-rc uses a predictable salt in its password hashing implementation, compromising the security of stored user credentials despite using a one-way hash function.

MitigationUpgrade Ktor to version 1.2.0-rc or later where the salt generation is properly randomized. Existing stored passwords should be re-hashed after the upgrade to ensure they use the improved salting mechanism.

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
KtorApplication
Affected:<= 1.1.5= 1.2.0

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
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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 checks

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

  1. Identify Ktor framework version
    Check your project dependencies (pom.xml, build.gradle, or equivalent) for the ktor dependency and note the version number
    Affected if The version is 1.1.5 or lower, or exactly 1.2.0 (non-rc)
  2. Locate UserHashedTableAuth configuration
    Search your codebase for references to UserHashedTableAuth, UserHashedTableAuthenticator, or similar class names in your authentication configuration files
    Affected if UserHashedTableAuth is used as the authentication mechanism
  3. Verify password hashing implementation
    Inspect the authentication configuration where users are defined - look for any user/credential table or hash configuration
    Affected if User credentials are stored with hashes using UserHashedTableAuth
  4. Confirm application uses authentication
    Review your application's routing and pipeline setup to confirm authentication is enforced on any endpoints
    Affected if The application has authenticated endpoints using the affected feature

You are affected if your application uses Ktor version 1.1.5 or lower (or exactly 1.2.0) AND uses UserHashedTableAuth for authentication of any endpoints.

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
Upgrade available Upgrade to a release after 1.1.5
Interim mitigation

Upgrade Ktor to version 1.2.0-rc or later where the salt generation is properly randomized. Existing stored passwords should be re-hashed after the upgrade to ensure they use the improved salting mechanism.

Fix this in Ktor Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

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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-2019-12737 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
  • No spam, self-promotion, credentials, or personal data