CVE-2023-0742Public exploitNetwork attack vector

Stored script execution via unescaped Markdown autolinks

Published Feb 8, 2023 · Updated Mar 25, 2025

Stored XSS in Apache Answer before 1.0.4 allows remote authenticated users to execute script in another user's browser through a post. The DangerousHTMLRenderer omitted a handler for Markdown autolinks, so crafted autolink URLs bypassed its URL-validation and HTML-escaping path. A low-privileged user must store the crafted content and a victim must view it; the script then runs with the victim's site privileges.

CVSS severity9.0
Critical
EPSS probability0.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Apache Answer before 1.0.4 allows remote authenticated users to execute script in another user's browser through a post. The DangerousHTMLRenderer omitted a handler for Markdown autolinks, so crafted autolink URLs bypassed its URL-validation and HTML-escaping path. A low-privileged user must store the crafted content and a victim must view it; the script then runs with the victim's site privileges.

The record

CVE
CVE-2023-0742
Published
Feb 8, 2023
Updated
Mar 25, 2025
Vendor
The Apache Software Foundation
Product
Apache Answer
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 8, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 25, 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.

  1. Affected versionversion=unspecified <1.0.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Apache Software Foundation · Apache Answerversion=unspecified <1.0.4

Published CVSS scores

8.0huntr.devCVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
9.0NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

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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