CVE-2020-24386Network attack vector

Cross-user email disclosure via unescaped IMAP tag

Published Jan 4, 2021 · Updated Aug 4, 2024

Information disclosure in Dovecot 2.2.26 through 2.3.11.3 allows remote authenticated users to access other users' email via IMAP IDLE. In src/imap/imap-client-hibernate.c, the server passes an unescaped attacker-controlled IMAP command tag to the imap-hibernate process, allowing crafted control characters to alter unhibernation parameters. Exploitation requires valid mail-server credentials and non-default IMAP hibernation, and it exposes other users' messages and filesystem paths.

CVSS severity8.2
High
EPSS probability2.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Dovecot 2.2.26 through 2.3.11.3 allows remote authenticated users to access other users' email via IMAP IDLE. In src/imap/imap-client-hibernate.c, the server passes an unescaped attacker-controlled IMAP command tag to the imap-hibernate process, allowing crafted control characters to alter unhibernation parameters. Exploitation requires valid mail-server credentials and non-default IMAP hibernation, and it exposes other users' messages and filesystem paths.

The record

CVE
CVE-2020-24386
Published
Jan 4, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-150, T1114
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 4, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.8NIST NVDCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
4.9NIST NVDAV:N/AC:M/Au:S/C:P/I:P/A:N
8.2OX Software GmbHCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-150Improper Neutralization of Escape, Meta, or Control Sequences
T1114Email Collection

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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