// For flags

CVE-2021-33515

dovecot: plaintext commands injection

Severity Score

4.8
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

The submission service in Dovecot before 2.3.15 allows STARTTLS command injection in lib-smtp. Sensitive information can be redirected to an attacker-controlled address.

El servicio de envío en Dovecot versiones anteriores a 2.3.15, permite la inyección de comandos STARTTLS en lib-smtp. La información confidencial puede ser redirigida a una dirección controlada por el atacante

It was found that dovecot could still accept plaintext commands while the STARTTLS negotiation process is ongoing. This could allow an active person in the middle, with valid credentials on dovecot, to, for example, steal confidential data such as the client's emails and passwords.

Kirin discovered that Dovecot incorrectly escaped kid and azp fields in JWT tokens. 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. Fabian Ising and Damian Poddebniak discovered that Dovecot incorrectly handled STARTTLS when using the SMTP submission service. A remote attacker could possibly use this issue to inject plaintext commands before STARTTLS negotiation. Various other issues were also addressed.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-05-24 CVE Reserved
  • 2021-06-21 CVE Published
  • 2024-08-03 CVE Updated
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection')
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Dovecot
Search vendor "Dovecot"
 Dovecot
Search vendor "Dovecot" for product "Dovecot"
 < 2.3.14.1
Search vendor "Dovecot" for product "Dovecot" and version " < 2.3.14.1"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 33
Search vendor "Fedoraproject" for product "Fedora" and version "33"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 34
Search vendor "Fedoraproject" for product "Fedora" and version "34"
-
Affected
Debian
Search vendor "Debian"
 Debian Linux
Search vendor "Debian" for product "Debian Linux"
 10.0
Search vendor "Debian" for product "Debian Linux" and version "10.0"
-
Affected