CVE-2021-29452Network attack vector

Cross-account modification via mischecked HAL-Form privileges

Published Apr 16, 2021 · Updated Aug 3, 2024

Incorrect authorization in Curveball a12n-server 0.18.0 through 0.18.1 allows remote authenticated users to edit other users via a HAL-Form. The user-edit HAL-Form evaluates the requester's privileges incorrectly, then applies submitted changes without enforcing administrator access. Any ordinary authenticated account can alter another user's record, but no unauthenticated access or availability impact is reported.

CVSS severity8.1
High
EPSS probability0.78%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Curveball a12n-server 0.18.0 through 0.18.1 allows remote authenticated users to edit other users via a HAL-Form. The user-edit HAL-Form evaluates the requester's privileges incorrectly, then applies submitted changes without enforcing administrator access. Any ordinary authenticated account can alter another user's record, but no unauthenticated access or availability impact is reported.

The record

CVE
CVE-2021-29452
Published
Apr 16, 2021
Updated
Aug 3, 2024
Vendor
Curveball
Product
a12n-server
Classifications
CWE-269, CWE-863, T1098
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 16, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 0.18 < 0.18.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Curveball · a12n-serverversion=>= 0.18 < 0.18.2

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
4.0NIST NVDAV:N/AC:L/Au:S/C:N/I:P/A:N
8.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/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.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-269Improper Privilege Management
CWE-863Incorrect Authorization
T1098Account Manipulation

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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