dbcve.org
IcalApplication · Apple

CVE-2004-1021

HIGH · 7.5 CVSS v2.0 Published 2005-03-01
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
iCal before 1.5.4 on Mac OS X 10.2.3, and other later versions, does not alert the user when handling calendars that use alarms, which allows attackers to execute programs and send e-mail via alarms.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

iCal versions prior to 1.5.4 on Mac OS X 10.2.3 and later contain a vulnerability where the application fails to alert or prompt the user before executing alarm-triggered actions. Attackers can exploit this by crafting malicious calendar files containing alarms that execute arbitrary programs or send emails without user interaction or awareness.

MitigationUpgrade iCal to version 1.5.4 or later. For legacy systems that cannot be upgraded, consider restricting calendar file imports from untrusted sources and disable alarm execution capabilities if feasible.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
IcalApplication
Affected:= 1.5.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial

AV:N/AC:L/Au:N/C:P/I:P/A:P

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed iCal version
    Open Finder, navigate to /Applications, right-click on iCal and select Get Info. Check the version number displayed under Name & Version.
    Affected if The version listed is 1.5.3 exactly
  2. Confirm Mac OS X version
    Click the Apple menu in the top-left corner, select About This Mac. Note the version number displayed.
    Affected if The system is running Mac OS X 10.2.3 or later (the OS version shown begins with 10.2.3 or higher)
  3. Verify iCal alarm execution capability
    Open iCal, go to the iCal menu, select Preferences, then click the Alerts tab. Check if alarm triggering is enabled.
    Affected if Alerts are enabled (any alarm action set to run a program or send an email could execute without user prompt)

You are affected if iCal version 1.5.3 is installed on Mac OS X 10.2.3 or later with alarm functionality enabled, as the malicious calendar file would execute alarm actions without prompting.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade iCal to version 1.5.4 or later. For legacy systems that cannot be upgraded, consider restricting calendar file imports from untrusted sources and disable alarm execution capabilities if feasible.

Fix this in Ical Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2004-1021 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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