CVE-2022-2778Network attack vector

Login rate-limit bypass via null-byte usernames

Published Sep 30, 2022 · Updated May 20, 2025

Rate-limit bypass in Octopus Deploy Octopus Server allows remote attackers to evade login throttling with null-byte login values. Octopus Deploy has not disclosed which login-processing component mishandles null bytes or how the rate-limit key diverges from authentication. The unauthenticated network path permits additional password attempts against an account, while successful access still requires valid credentials.

CVSS severity9.8
Critical
EPSS probability0.76%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Rate-limit bypass in Octopus Deploy Octopus Server allows remote attackers to evade login throttling with null-byte login values. Octopus Deploy has not disclosed which login-processing component mishandles null bytes or how the rate-limit key diverges from authentication. The unauthenticated network path permits additional password attempts against an account, while successful access still requires valid credentials.

The record

CVE
CVE-2022-2778
Published
Sep 30, 2022
Updated
May 20, 2025
Vendor
Octopus Deploy
Product
Octopus Server
Classifications
T1110
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 30, 2022CVE publishedPublication date reported by the CVE source.
  2. May 20, 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=2022.3.348 <unspecified
  2. Affected versionversion=2022.4.791 <unspecified
  3. Affected versionversion=3.0 <unspecified
  4. Affected versionversion=unspecified <2022.2.8277
  5. Affected versionversion=unspecified <2022.3.10586
  6. Affected versionversion=unspecified <2022.4.1371

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Octopus Deploy · Octopus Serverversion=2022.3.348 <unspecified; version=2022.4.791 <unspecified; version=3.0 <unspecified; version=unspecified <2022.2.8277; version=unspecified <2022.3.10586; version=unspecified <2022.4.1371

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1110Brute Force

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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