CVE-2021-27099Network attack vector

Arbitrary identity issuance via normalized agent path

Published Mar 5, 2021 · Updated Aug 3, 2024

Path normalization in affected SPIRE releases through 0.12.0 allows attackers to obtain arbitrary SPIFFE IDs via crafted EC2 tags. The aws_iid Node Attestor normalizes a templated agent-ID path containing the tag value, causing crafted path elements to resolve to a different identity. Exploitation requires control of the tag before attestation, agent ID templating, and placement of the tag value at the path's final element; issuance remains within the same trust domain.

CVSS severity6.8
Medium
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path normalization in affected SPIRE releases through 0.12.0 allows attackers to obtain arbitrary SPIFFE IDs via crafted EC2 tags. The aws_iid Node Attestor normalizes a templated agent-ID path containing the tag value, causing crafted path elements to resolve to a different identity. Exploitation requires control of the tag before attestation, agent ID templating, and placement of the tag value at the path's final element; issuance remains within the same trust domain.

The record

CVE
CVE-2021-27099
Published
Mar 5, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-706, CWE-863
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 5, 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.9NIST National Vulnerability DatabaseAV:N/AC:M/Au:S/C:P/I:P/A:N
6.8NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-706Use of Incorrectly-Resolved Name or Reference
CWE-863Incorrect Authorization

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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