CVE-2021-37759Network attack vector

Privilege escalation via leaked session IDs

Published Jul 31, 2021 · Updated Aug 4, 2024

Sensitive information disclosure in Graylog before 4.1.2 allows remote attackers to escalate privileges via exposed session IDs. Graylog writes active session IDs to DEBUG messages and the Enterprise audit log, allowing a party that reads those logs to reuse an ID as the corresponding authenticated session. DEBUG logging is disabled by default and the audit log is normally restricted to Graylog administrators, so exploitation requires access to a log containing an active or previously active session ID.

CVSS severity9.8
Critical
EPSS probability1.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Sensitive information disclosure in Graylog before 4.1.2 allows remote attackers to escalate privileges via exposed session IDs. Graylog writes active session IDs to DEBUG messages and the Enterprise audit log, allowing a party that reads those logs to reuse an ID as the corresponding authenticated session. DEBUG logging is disabled by default and the audit log is normally restricted to Graylog administrators, so exploitation requires access to a log containing an active or previously active session ID.

The record

CVE
CVE-2021-37759
Published
Jul 31, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-532, T1552.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 31, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

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-532Insertion of Sensitive Information into Log File
T1552.001Credentials from Files

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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