QID 198412

Date Published: 2021-06-28

QID 198412: Ubuntu Security Notification for Dovecot vulnerabilities (USN-4993-1)

Dovecot incorrectly escaped kid and azp fields in jwt tokens.
Dovecot incorrectly handled starttls when using the smtp submission service.

Note: The preceding description block is extracted directly from the security advisory. Using automation, we have attempted to clean and format it as much as possible without introducing additional issues.

a local attacker could possibly use this issue to validate tokens using arbitrary keys.
This issue only affected ubuntu 20.10 and ubuntu 21.04. (
Cve-2021-29157).
A remote attacker could possibly use this issue to inject plaintext commands before starttls negotiation. (
Cve-2021-33515).

  • CVSS V3 rated as Medium - 5.5 severity.
  • CVSS V2 rated as Medium - 5.8 severity.
    • Solution
    Refer to Ubuntu advisory: USN-4993-1 for affected packages and patching details, or update with your package manager.
    Vendor References

    CVEs related to QID 198412

    CVE-2021-33515 | CVE-2021-29157 |
    Software Advisories
    Advisory ID Software Component Link
    USN-4993-1 Ubuntu Linux URL Logo usn.ubuntu.com/4993-1
    By selecting these links, you may be leaving CVEreport webspace. We have provided these links to other websites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other websites that are more appropriate for your purpose. CVEreport does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, CVEreport does not endorse any commercial products that may be mentioned on these sites. Please address comments about any linked pages to [email protected].