CVE-2022-0217Network attack vector

Unauthenticated service hang via recursive entity expansion

Published Aug 26, 2022 · Updated Aug 2, 2024

Denial of service in Prosody before 0.11.12 allows remote attackers to hang the XMPP server through its WebSocket endpoint. The WebSocket module passes pre-authentication XML frames to util/xml.lua, whose libexpat parser permits recursive DTD entity expansion and does not yield while processing a complete frame. WebSockets must be enabled and exposed to an untrusted party; normal XMPP and BOSH connections are unaffected, and XXE injection depends on the linked libexpat version.

CVSS severity7.5
High
EPSS probability5.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Prosody before 0.11.12 allows remote attackers to hang the XMPP server through its WebSocket endpoint. The WebSocket module passes pre-authentication XML frames to util/xml.lua, whose libexpat parser permits recursive DTD entity expansion and does not yield while processing a complete frame. WebSockets must be enabled and exposed to an untrusted party; normal XMPP and BOSH connections are unaffected, and XXE injection depends on the linked libexpat version.

The record

CVE
CVE-2022-0217
Published
Aug 26, 2022
Updated
Aug 2, 2024
Vendor
Prosody IM
Product
Prosody
Classifications
CWE-611, CWE-776, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 26, 2022CVE 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=Fixed in prosody 0.11.12, Affects all versions with support for WebSockets.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Prosody IM · Prosodyversion=Fixed in prosody 0.11.12, Affects all versions with support for WebSockets.

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.3Prosody IMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:F/RL:X/RC:C

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-611Improper Restriction of XML External Entity Reference
CWE-776Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
T1499.004Application or System Exploitation

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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