CVE-2021-31232

Local file disclosure via unchecked configuration paths

Published Apr 30, 2021 · Updated Aug 3, 2024

Improper input validation in CNCF Cortex Alertmanager before 1.8.1 allows local users to disclose files through crafted API configuration. The API accepts filesystem paths in password_file and template settings without restricting them to tenant-managed files, causing Alertmanager to read and forward the referenced contents through a webhook. Exploitation requires the experimental Alertmanager API and low-privilege configuration access; exposure is limited to files readable by the service account.

CVSS severity5.5
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in CNCF Cortex Alertmanager before 1.8.1 allows local users to disclose files through crafted API configuration. The API accepts filesystem paths in password_file and template settings without restricting them to tenant-managed files, causing Alertmanager to read and forward the referenced contents through a webhook. Exploitation requires the experimental Alertmanager API and low-privilege configuration access; exposure is limited to files readable by the service account.

The record

CVE
CVE-2021-31232
Published
Apr 30, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 30, 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 vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

2.1NVDAV:L/AC:L/Au:N/C:P/I:N/A:N
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1005Data from Local System

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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