CVE-2023-49782Network attack vector

Cross-site scripting via unescaped proxy errors

Published Dec 8, 2023 · Updated Aug 2, 2024

Cross-site scripting in Collabora Online before 23.5.601 allows remote attackers to execute script in a user's browser via proxy.php. The proxy.php errorExit function inserted attacker-controlled error text directly into an HTML response without escaping; the corrected code applies htmlspecialchars before output. Exploitation requires a user to load the crafted error response, giving the script access to the affected Nextcloud origin.

CVSS severity7.1
High
EPSS probability0.41%
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 Collabora Online before 23.5.601 allows remote attackers to execute script in a user's browser via proxy.php. The proxy.php errorExit function inserted attacker-controlled error text directly into an HTML response without escaping; the corrected code applies htmlspecialchars before output. Exploitation requires a user to load the crafted error response, giving the script access to the affected Nextcloud origin.

The record

CVE
CVE-2023-49782
Published
Dec 8, 2023
Updated
Aug 2, 2024
Vendor
Collabora Productivity
Product
Collabora Online
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 8, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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=< 23.5.601

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Collabora Productivity · Collabora Onlineversion=< 23.5.601

Published CVSS scores

7.1GitHub CNACVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

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.

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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.

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Technologies

Your stack

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Your stack

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