What’s Vulnerable › Vulnerabilities

CVE-2020-24386

• Severity: medium (CVSS 6.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-01-04 · updated 2026-06-17

Description

An issue was discovered in Dovecot before 2.3.13. By using IMAP IDLE, an authenticated attacker can trigger unhibernation via attacker-controlled parameters, leading to access to other users' email messages (and path disclosure).

Affected products

• Debian Linux: 10.0
• dovecot: from 2.2.26 before 2.3.13 — fixed in 2.3.13
• Fedoraproject Fedora: 32

How to fix

Upgrade to a fixed version: dovecot 2.3.13. Check the vendor advisory for mitigations.

References

• http://packetstormsecurity.com/files/160842/Dovecot-2.3.11.3-Access-Bypass.html
• http://seclists.org/fulldisclosure/2021/Jan/18
• http://www.openwall.com/lists/oss-security/2021/01/04/4
• https://doc.dovecot.org/configuration_manual/hibernation/
• https://dovecot.org/pipermail/dovecot-news/2021-January/000450.html
• https://dovecot.org/security
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GXDKFLOCUP7I4ELGQ2F4P5TGC6NXMYV7/
• https://security.gentoo.org/glsa/202101-01
• https://www.debian.org/security/2021/dsa-4825
• http://packetstormsecurity.com/files/160842/Dovecot-2.3.11.3-Access-Bypass.html
• http://seclists.org/fulldisclosure/2021/Jan/18
• http://www.openwall.com/lists/oss-security/2021/01/04/4

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