CVE-2021-27099

In SPIRE before versions 0.8.5, 0.9.4, 0.10.2, 0.11.3 and 0.12.1, the "aws_iid" Node Attestor improperly normalizes the path provided through the agent ID templating feature, which may allow the issuance of an arbitrary SPIFFE ID within the same trust domain, if the attacker controls the value of an EC2 tag prior to attestation, and the attestor is configured for agent ID templating where the tag value is the last element in the path. This issue has been fixed in SPIRE versions 0.11.3 and 0.12.1

Published: 2021-03-05 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-27099 is rated Moderate Risk (41.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.21%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-27099

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-30 0.41% 0.21% -0.20%
2 2025-03-29 0.21% 0.41% +0.20%
3 2025-03-17 — 0.21% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-27099

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 1.6 5.2 [email protected]
4.9 2.0 MEDIUM
AV:N/AC:M/Au:S/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 6.8 4.9 [email protected]

Weakness enumeration for CVE-2021-27099

Affected software / configurations for CVE-2021-27099

Vendor Product Version Raw CPE
cncf spire < 0.8.5 cpe:2.3:a:cncf:spire:*:*:*:*:*:*:*:*
cncf spire >= 0.9.0, < 0.9.4 cpe:2.3:a:cncf:spire:*:*:*:*:*:*:*:*
cncf spire >= 0.10.0, < 0.10.2 cpe:2.3:a:cncf:spire:*:*:*:*:*:*:*:*
cncf spire >= 0.11.0, < 0.11.3 cpe:2.3:a:cncf:spire:*:*:*:*:*:*:*:*
cncf spire >= 0.12.0, < 0.12.1 cpe:2.3:a:cncf:spire:*:*:*:*:*:*:*:*

References for CVE-2021-27099

cvelogic Threat Intelligence