MircApplication · Khaled Mardam Bey

CVE-2002-0425

MEDIUM · 5.0 CVSS v2.0 Published 2002-08-12
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
59/100
Remediation priority · Elevated
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
mIRC DCC server protocol allows remote attackers to gain sensitive information such as alternate IRC nicknames via a "100 testing" message in a DCC connection request that cannot be ignored or canceled by the user, which may leak the alternate nickname in a response message.

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

mIRC's DCC (Direct Client-to-Client) server protocol contains an information disclosure vulnerability. Attackers can send a crafted '100 testing' message in a DCC connection request that the user cannot ignore or cancel. This causes mIRC to leak alternate IRC nicknames in the response, allowing remote attackers to enumerate a user's alternate identities.

MitigationThe vulnerability requires a fix in the mIRC client software itself to properly handle and ignore malicious DCC '100 testing' messages. Users should consider blocking unsolicited DCC connections at the firewall level as a temporary workaround until the vendor releases a patch.

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
MircApplication
Affected:= 6.0= 6.0_1

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
None
Availability
None

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

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. Verify mIRC is installed
    Locate the mIRC executable on the system (commonly in Program Files) or check for mIRC in the list of installed programs
    Affected if mIRC is present on the system
  2. Identify the installed mIRC version
    Check the version of the installed mIRC client (typically available in the application properties or help/about section)
    Affected if The version is 6.0 or 6.0_1 specifically
  3. Confirm the DCC feature is available
    Verify that the DCC (Direct Client-to-Client) functionality exists in the installed mIRC version - this is a core protocol feature of mIRC for direct connections
    Affected if DCC is available (this is standard in mIRC)
  4. Test for the information disclosure condition
    When an unsolicited DCC connection request containing the specific '100 testing' message is received, observe whether mIRC responds with alternate nicknames - this requires monitoring network traffic or testing with a crafted DCC request
    Affected if The system responds to a DCC '100 testing' message with alternate nickname information that should not be disclosed

The user is affected if mIRC version 6.0 or 6.0_1 is installed and the DCC protocol processes the crafted '100 testing' message, causing alternate nicknames to leak in the response.

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

The vulnerability requires a fix in the mIRC client software itself to properly handle and ignore malicious DCC '100 testing' messages. Users should consider blocking unsolicited DCC connections at the firewall level as a temporary workaround until the vendor releases a patch.

Fix this in Mirc Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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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-2002-0425 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
  • No spam, self-promotion, credentials, or personal data