CVE-2021-33515

Name: CVE-2021-33515
Creator: NVD / NIST
Published: 2021-06-28T13:15:20.96+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.8/10EPSS 2.84%

Last modified Jun 17, 2026

CVE-2021-33515 is a medium-severity vulnerability rated 4.8/10 on the CVSS scale. 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.. EPSS estimates a 2.84% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

4.8/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

EPSS Probability

2.84%

84.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-77

Affected Software

Vendor	Product	Versions
Dovecot	Dovecot	< 2.3.14.1
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34
Debian	Debian Linux	10.0

References

https://dovecot.org/securityVendor Advisory
https://lists.debian.org/debian-lts-announce/2022/09/msg00032.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JB2VTJ3G2ILYWH5Y2FTY2PUHT2MD6VMI/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TK424DWFO2TKJYXZ2H3XL633TYJL4GQN/
https://security.gentoo.org/glsa/202107-41Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/06/28/2Mailing List, Third Party Advisory
https://dovecot.org/securityVendor Advisory
https://lists.debian.org/debian-lts-announce/2022/09/msg00032.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JB2VTJ3G2ILYWH5Y2FTY2PUHT2MD6VMI/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TK424DWFO2TKJYXZ2H3XL633TYJL4GQN/
https://security.gentoo.org/glsa/202107-41Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/06/28/2Mailing List, Third Party Advisory

Timeline

Published: Jun 28, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-33515?

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.

How severe is CVE-2021-33515?

CVE-2021-33515 has a CVSS score of 4.8/10 (MEDIUM severity). The EPSS model estimates a 2.84% probability of exploitation in the next 30 days.

How do I fix CVE-2021-33515?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-33515?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST