CVE-2021-27924Network attack vector

User impersonation via unredacted session-cookie logging

Published May 19, 2021 · Updated Aug 3, 2024

Sensitive-data exposure in Couchbase Server 6.x through 6.6.1 allows attackers to impersonate users with unexpired session cookies. The Server UI writes temporary session cookies without redaction to the audit log and debug.log when audited events contain a session ID. Exploitation requires access to logging data before the recorded cookie expires; the resulting access impersonates the authenticated user.

CVSS severity5.9
Medium
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Sensitive-data exposure in Couchbase Server 6.x through 6.6.1 allows attackers to impersonate users with unexpired session cookies. The Server UI writes temporary session cookies without redaction to the audit log and debug.log when audited events contain a session ID. Exploitation requires access to logging data before the recorded cookie expires; the resulting access impersonates the authenticated user.

The record

CVE
CVE-2021-27924
Published
May 19, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-319, T1539
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 19, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:P/I:N/A:N
5.9NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/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-319Cleartext Transmission of Sensitive Information
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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