CVE-2021-23347Network attack vector

CLI cross-site scripting via unescaped SSO errors

Published Mar 3, 2021 · Updated Sep 17, 2024

Cross-site scripting in Argo Project Argo CD CLI before 1.7.13 and 1.8.0 through 1.8.5 allows attackers to execute JavaScript via SSO errors. The oauth2Login callback in cmd/argocd/commands/login.go writes SSO error and error_description values to an HTTP error response without HTML escaping. Exploitation requires a malicious or compromised SSO provider to return a crafted error while a user signs in through the CLI, causing script execution in the local callback page.

CVSS severity4.7
Medium
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Argo Project Argo CD CLI before 1.7.13 and 1.8.0 through 1.8.5 allows attackers to execute JavaScript via SSO errors. The oauth2Login callback in cmd/argocd/commands/login.go writes SSO error and error_description values to an HTTP error response without HTML escaping. Exploitation requires a malicious or compromised SSO provider to return a crafted error while a user signs in through the CLI, causing script execution in the local callback page.

The record

CVE
CVE-2021-23347
Published
Mar 3, 2021
Updated
Sep 17, 2024
Vendor
Argo Project
Product
Argo CD
Classifications
CWE-79, T1203
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Mar 3, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=1.8.0 <unspecified
  2. Affected versionversion=unspecified <1.7.13
  3. Affected versionversion=unspecified <1.8.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Argo Project · Argo CDversion=1.8.0 <unspecified; version=unspecified <1.7.13; version=unspecified <1.8.6

Published CVSS scores

3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/A:N
4.7Snyk CNACVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L
4.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

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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