SMTP command injection via unvalidated iCalendar addresses
Published Jul 5, 2022 · Updated Apr 22, 2025
SMTP command injection in Nextcloud Server before 22.2.8, 23.0.0 through 23.0.4, and 24.0.0 allows remote authenticated users to send email. The CalDAV backend accepts newline-bearing email addresses from iCalendar data without validation and passes them into an authenticated SMTP session. Exploitation requires a low-privileged account, victim interaction, and a compatible SMTP backend; consequences include forged sender identities and attacker-chosen email.
Summary
What happened
SMTP command injection in Nextcloud Server before 22.2.8, 23.0.0 through 23.0.4, and 24.0.0 allows remote authenticated users to send email. The CalDAV backend accepts newline-bearing email addresses from iCalendar data without validation and passes them into an authenticated SMTP session. Exploitation requires a low-privileged account, victim interaction, and a compatible SMTP backend; consequences include forged sender identities and attacker-chosen email.
The record
- CVE
- CVE-2022-31014
- Published
- Jul 5, 2022
- Updated
- Apr 22, 2025
- Vendor
- Nextcloud GmbH
- Product
- Security Advisories
- Classifications
- CWE-93, CWE-74, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 5, 2022CVE publishedPublication date reported by the CVE source.
- Apr 22, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 22.2.8
- Affected versionversion=>= 23.0.0, < 23.0.5
- Affected versionversion=>= 24.0.0, < 24.0.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- Public HackerOne proof of conceptproof of concept · unverified
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Technologies
Your stack
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Your stack
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