CVE-2009-3724Network attack vector

Cross-site scripting via unsafe image references

Published Jan 15, 2020 · Updated Aug 7, 2024

Cross-site scripting in markdown2 before 1.0.1.14 allows remote attackers to execute script in rendered HTML via crafted Markdown. The renderer mishandles attacker-controlled image references and HTML chunks, allowing quote-crafted attributes to pass into generated markup without adequate neutralization. Exploitation requires a web application to render attacker-supplied Markdown and a victim to load the resulting page, enabling script execution in the victim's browser.

CVSS severity6.1
Medium
EPSS probability0.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in markdown2 before 1.0.1.14 allows remote attackers to execute script in rendered HTML via crafted Markdown. The renderer mishandles attacker-controlled image references and HTML chunks, allowing quote-crafted attributes to pass into generated markup without adequate neutralization. Exploitation requires a web application to render attacker-supplied Markdown and a victim to load the resulting page, enabling script execution in the victim's browser.

The record

CVE
CVE-2009-3724
Published
Jan 15, 2020
Updated
Aug 7, 2024
Vendor
Trent Mick
Product
markdown2
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 15, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 7, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=before 1.0.1.14

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Trent Mick · markdown2version=before 1.0.1.14

Published CVSS scores

6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NVDAV:N/AC:M/Au:N/C:N/I:P/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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