Security readout for executives and security teams
Plain-English summary
Affected Nextcloud Server versions can let an authenticated attacker abuse email generation involving iCalendar attachments to inject SMTP commands. Business impact depends on the mail server, but could include unauthorized emails or spoofed sender behavior through Nextcloud’s authenticated SMTP session.
Executive priority
Address in the normal vulnerability remediation cycle, with faster handling for externally exposed or business-critical Nextcloud deployments. The issue is not rated critical, but it affects trusted email-sending paths and could create reputational and phishing risk.
Technical view
The issue is SMTP command injection caused by unsanitized newline handling in iCalendar email attachment flows. CVSS 5.4 reflects network access, low privileges, required user interaction, changed scope, and limited confidentiality and integrity impact. Fixed releases are 22.2.8, 23.0.5, and 24.0.1.
Likely exposure
Exposure is likely limited to Nextcloud Server deployments on versions before 22.2.8, 23.0.5, or 24.0.1 that use backend SMTP. Risk is higher where Nextcloud can send mail through an authenticated SMTP account.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. Exploitation requires at least low privileges and user interaction according to the CVSS vector, and the final impact depends on which SMTP commands the backend server accepts.
Researcher notes
Focus validation on version evidence and SMTP configuration. The public summary identifies newline sanitization failure and authenticated SMTP session hijacking risk, but the provided bundle does not include enough detail to assert exploit reliability across SMTP backends.
Mitigation direction
- Upgrade Nextcloud Server to 22.2.8, 23.0.5, 24.0.1, or later.
- Treat upgrade as required; the advisory states there are no known workarounds.
- Prioritize internet-accessible or broadly used Nextcloud instances that send calendar-related email.
- Review SMTP account activity for unexpected mail, sender changes, or unusual recipients.
Validation and detection
- Inventory Nextcloud Server versions across production, staging, and managed customer environments.
- Confirm no instance remains on 22.x before 22.2.8, 23.0.0-23.0.4, or 24.0.0.
- Verify the patched version is running after maintenance, not only downloaded or staged.
- Check Nextcloud mail and SMTP logs for unusual outbound email around suspected exposure windows.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-74: Exact CWE lookup
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Open ATT&CK lookupCWE-93: Exact CWE lookup
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Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2022-31014 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N2.32.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-264h-3v4w-6xh2CVE reference · x_refsource_CONFIRM
- https://github.com/nextcloud/server/pull/32428CVE reference · x_refsource_MISC
- https://hackerone.com/reports/1516377CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Improper Neutralization of CRLF Sequences ('CRLF Injection')
Improper Neutralization of CRLF Sequences ('CRLF Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.