Rancher Login Component errorMsg Parameter Vulnerability [CVE-2019-11881]

CVE Number – CVE-2019-11881

A vulnerability in the login component of Rancher could allow an unauthenticated, remote attacker to gain unauthorized access on a targeted system.The vulnerability exists because the errorMsg parameter of affected software can be tampered with to display arbitrary content. An attacker could exploit this vulnerability by persuading a user to visit phishing sites, which the attacker could use to access sensitive information and gain unauthorized access to the affected software. A successful exploit could be used to conduct further attacks.Proof-of-concept (PoC) code that demonstrates an exploit of this vulnerability is publicly available.Rancher has confirmed the vulnerability and released software updates.


  • To exploit this vulnerability, an attacker may use misleading language or instructions to persuade a user to access a link that directs the user to a malicious site.


  • Administrators are advised to apply the appropriate updates.

    Administrators are advised to allow only trusted users to have network access.

    Administrators are advised to use an unprivileged account when browsing the Internet.

    Administrators are advised to monitor critical systems.

    Users are advised not to open email messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in email messages are safe, they are advised not to open them.

    Users are advised not to visit websites or follow links that have suspicious characteristics or cannot be verified as safe.

Vendor Announcements

  • Rancher has released a security announcement at the following link: CVE-2019-11881

Fixed Software

Jason Davies

UK based technology professional, with an interest in computer security and telecoms.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: