CVE-2022-21691Network attack vector

Chat eavesdropping via spoofed leave events

Published Jan 18, 2022 · Updated Apr 23, 2025

Improper access control in OnionShare 2.3 through 2.4 allows attackers to fake leaving a chat while retaining access. The server accepts a disconnect event from an unlisted client and removes the matching displayed user without ending that user's original session. The attacker must already have access to the chat environment; the deception preserves access to later messages and can enable message injection through a related flaw.

CVSS severity5.3
Medium
EPSS probability0.68%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in OnionShare 2.3 through 2.4 allows attackers to fake leaving a chat while retaining access. The server accepts a disconnect event from an unlisted client and removes the matching displayed user without ending that user's original session. The attacker must already have access to the chat environment; the deception preserves access to later messages and can enable message injection through a related flaw.

The record

CVE
CVE-2022-21691
Published
Jan 18, 2022
Updated
Apr 23, 2025
Vendor
OnionShare
Product
OnionShare
Classifications
CWE-306, T1036
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 18, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 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=< 2.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OnionShare · OnionShareversion=< 2.5

Published CVSS scores

5.3GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
4.0NIST NVDAV:N/AC:L/Au:S/C:N/I:P/A:N
4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1036Masquerading

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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