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Social Network KitApplication · Humhub

CVE-2019-12743

MEDIUM · 5.3 CVSS v3.0 Published 2019-07-29
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
HumHub Social Network Kit Enterprise v1.3.13 allows remote attackers to find the user accounts existing on any Social Network Kits (including self-hosted ones) by brute-forcing the username after the /u/ initial URI substring, aka Response Discrepancy Information Exposure.

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

HumHub Social Network Kit Enterprise v1.3.13 contains an information disclosure vulnerability where the application returns different HTTP responses (status codes or body content) for valid versus invalid usernames when brute-forcing the /u/ URI path. This allows remote attackers to enumerate valid user accounts by observing response discrepancies.

MitigationImplement consistent HTTP responses for both valid and invalid usernames (generic error messages), combined with rate limiting or CAPTCHA after failed enumeration attempts to prevent automated username discovery.

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
Social Network KitApplication
Affected:= 1.3.13

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:3.0/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. Confirm HumHub version
    Access the admin dashboard and navigate to Administration > Information, or check the file /protected/config/common.php for the version number, or view the footer of any HumHub page which often displays the version.
    Affected if The installed version is exactly 1.3.13 (HumHub Social Network Kit Enterprise)
  2. Identify if /u/ endpoint exists
    Attempt to access your HumHub installation at the URI /u/ followed by a known-valid username (e.g., /u/admin) and a random non-existent username (e.g., /u/thisuserdoesnotexist123).
    Affected if Both URLs return HTTP 200 but with visibly different page content or the valid username returns a user profile page while the invalid returns an error.
  3. Compare HTTP status codes
    Send HTTP GET requests to /u/[valid_user] and /u/[invalid_user] and compare the response status codes using a tool like curl or browser developer tools.
    Affected if The valid username returns a different status code (e.g., 200) than the invalid username (e.g., 404 or 302 redirect), indicating the application confirms user existence.
  4. Compare response body content
    Examine the full HTML response bodies from both /u/ requests and look for differences in error messages, page titles, or whether a user profile is rendered.
    Affected if The response body differs significantly between valid and invalid usernames, allowing an attacker to programmatically distinguish valid accounts.
  5. Check for rate limiting or CAPTCHA on /u/ path
    Review the web server configuration (Apache/Nginx) and application-level rate limiting settings, or attempt multiple rapid requests to /u/ to see if requests are blocked or challenged.
    Affected if No rate limiting, CAPTCHA, or account lockout is enforced on the /u/ endpoint, meaning automated enumeration can proceed unhindered.

Your environment is affected if HumHub Social Network Kit Enterprise version 1.3.13 is installed AND the /u/ endpoint returns distinguishable responses between valid and invalid usernames, allowing an attacker to enumerate valid user accounts through automated requests.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement consistent HTTP responses for both valid and invalid usernames (generic error messages), combined with rate limiting or CAPTCHA after failed enumeration attempts to prevent automated username discovery.

Fix this in Social Network Kit Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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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-2019-12743 in production — separate from our analysis above.

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