CVE-2021-31820Network attack vector

Proxy credential disclosure via plaintext UI rendering

Published Aug 18, 2021 · Updated Aug 3, 2024

Cleartext credential exposure in Octopus Server after 2018.8.2 allows remote attackers to read an authenticated proxy password in the UI. When Web Request Proxy authentication is configured, the UI renders the stored password as plaintext rather than concealing it. Exposure requires that proxy configuration and discloses its credential without altering data or interrupting service.

CVSS severity7.5
High
EPSS probability0.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cleartext credential exposure in Octopus Server after 2018.8.2 allows remote attackers to read an authenticated proxy password in the UI. When Web Request Proxy authentication is configured, the UI renders the stored password as plaintext rather than concealing it. Exposure requires that proxy configuration and discloses its credential without altering data or interrupting service.

The record

CVE
CVE-2021-31820
Published
Aug 18, 2021
Updated
Aug 3, 2024
Vendor
Octopus Deploy
Product
Octopus Server
Classifications
CWE-312, T1555
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 18, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=2018.8.2 <unspecified
  2. Affected versionversion=2021.1.7149 <unspecified
  3. Affected versionversion=unspecified <2020.6.5310
  4. Affected versionversion=unspecified <2021.1.7622

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Octopus Deploy · Octopus Serverversion=2018.8.2 <unspecified; version=2021.1.7149 <unspecified; version=unspecified <2020.6.5310; version=unspecified <2021.1.7622

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-312Cleartext Storage of Sensitive Information
T1555Credentials from Password Stores

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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