CVE-2022-21689Public exploitNetwork attack vector

Upload interruption via second-granularity directory collisions

Published Jan 18, 2022 · Updated Apr 23, 2025

Denial of service in OnionShare before 2.5 allows remote attackers to interrupt Receive mode file uploads via concurrent requests. ReceiveModeRequest derives upload directory names with one-second precision and stops after 100 same-second name collisions, marking later uploads as errors. Access to the Receive service is required; public mode removes URL secrecy as a gate, and the bounded consequence is interrupted uploads rather than a process crash.

CVSS severity8.7
High
EPSS probability1.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in OnionShare before 2.5 allows remote attackers to interrupt Receive mode file uploads via concurrent requests. ReceiveModeRequest derives upload directory names with one-second precision and stops after 100 same-second name collisions, marking later uploads as errors. Access to the Receive service is required; public mode removes URL secrecy as a gate, and the bounded consequence is interrupted uploads rather than a process crash.

The record

CVE
CVE-2022-21689
Published
Jan 18, 2022
Updated
Apr 23, 2025
Vendor
OnionShare
Product
OnionShare
Classifications
T1499.003
Attack vector
network
Privileges
unauthenticated

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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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 privilegesunauthenticated

What is affected?

OnionShare · OnionShareversion=< 2.5

Published CVSS scores

8.7GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
7.5GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499.003Application Exhaustion Flood

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo