dbcve.org
UseradmApplication · Northern.tech

CVE-2021-35342

HIGH · 7.5 CVSS v3.1 Published 2021-08-27
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
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
The useradm service 1.14.0 (in Northern.tech Mender Enterprise 2.7.x before 2.7.1) and 1.13.0 (in Northern.tech Mender Enterprise 2.6.x before 2.6.1) allows users to access the system with their JWT token after logout, because of missing invalidation (if the JWT verification cache is enabled).

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

The useradm service in Mender Enterprise 2.6.x and 2.7.x fails to invalidate JWT tokens upon user logout when JWT verification caching is enabled, allowing authenticated access to persist after logout using the cached token verification.

MitigationUpgrade Mender Enterprise to version 2.7.1 or 2.6.1, or disable the JWT verification cache as a workaround until patching is possible.

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
UseradmApplication
Affected:= 1.14.0= 1.13.0

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
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/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 checks

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

  1. Identify useradm service installation
    Check if the useradm service is installed: on systemd systems run 'systemctl list-unit-files | grep useradm' or check for the binary at /usr/bin/useradm or /usr/local/bin/useradm
    Affected if The useradm service is not present, then this CVE does not apply
  2. Determine useradm version
    Run 'useradm --version' or check the package version via 'dpkg -l | grep useradm' (Debian) or 'rpm -qa | grep useradm' (RHEL/CentOS)
    Affected if The installed version is exactly 1.13.0 or 1.14.0, proceed to next check
  3. Locate useradm configuration file
    Common config paths: /etc/useradm/useradm.conf, /etc/mender/useradm.conf, or check the service init script for config path via 'systemctl show useradm'
    Affected if Configuration file location is found, continue to JWT cache check
  4. Verify JWT verification cache configuration
    Inspect the config file for JWT cache settings: look for keys like 'JWT_CACHE', 'jwt_cache', 'verification_cache_enabled', or 'CacheVerifyJwt' set to true/yes/1
    Affected if JWT verification caching is explicitly enabled (value is true, yes, or 1) in the configuration file, then the environment is affected by this CVE

If useradm version is 1.13.0 or 1.14.0 AND JWT verification caching is enabled in the configuration, the environment is vulnerable to persistent authentication after logout.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Mender Enterprise to version 2.7.1 or 2.6.1, or disable the JWT verification cache as a workaround until patching is possible.

Recommended fix High confidence

Mender Enterprise 2.7.1 or Mender Enterprise 2.6.1 (containing fixed useradm 1.14.x and 1.13.x respectively)

  1. Upgrade Mender Enterprise 2.7.x to version 2.7.1 or later to obtain the fixed useradm service
  2. Upgrade Mender Enterprise 2.6.x to version 2.6.1 or later to obtain the fixed useradm service
  3. After upgrade, verify that JWT tokens are properly invalidated upon user logout
  4. Alternatively, if immediate upgrade is not possible, disable the JWT verification cache in the useradm configuration to mitigate the session expiration issue
Caveat Standard upgrade precautions apply - review release notes and test in staging environment before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Useradm Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
6.0 hours of engineering $1,060
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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-2021-35342 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