CVE-2021-3509Network attack vector

Session-token theft via unescaped Swagger callback

Published May 26, 2021 · Updated Aug 3, 2024

Cross-site scripting in Ceph Dashboard allows remote attackers to steal JWT session tokens through generated API documentation pages. The docs.py Swagger generator reads a token cookie, header, or request value and interpolates it unescaped into an onComplete JavaScript callback. Published assessments disagree on user interaction, and Red Hat states its Storage 4 build lacks the prerequisite cookie change and is not affected.

CVSS severity8.1
High
EPSS probability1.70%
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 Ceph Dashboard allows remote attackers to steal JWT session tokens through generated API documentation pages. The docs.py Swagger generator reads a token cookie, header, or request value and interpolates it unescaped into an onComplete JavaScript callback. Published assessments disagree on user interaction, and Red Hat states its Storage 4 build lacks the prerequisite cookie change and is not affected.

The record

CVE
CVE-2021-3509
Published
May 26, 2021
Updated
Aug 3, 2024
Vendor
389 Directory Server
Product
Red Hat Ceph Storage
Classifications
CWE-79, T1539
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 26, 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=as shipped in Red Hat Ceph Storage 4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

389 Directory Server · Red Hat Ceph Storageversion=as shipped in Red Hat Ceph Storage 4

Published CVSS scores

6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
8.8SUSECVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.1Red HatCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
4.3NVDAV:N/AC:M/Au:N/C:N/I:P/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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1539Steal Web Session Cookie

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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