CVE-2021-32281Public exploit

Code execution via out-of-bounds upvalue read

Published Sep 20, 2021 · Updated Aug 3, 2024

Heap-buffer overflow in Creolabs Gravity 0.8.1 and earlier allows local users to execute code by compiling a crafted Gravity source file. During semantic analysis, gnode_function_add_upvalue reads two bytes four bytes beyond a heap allocation while resolving an identifier's captured upvalue. Exploitation requires a user to compile the crafted file; the public proof of concept demonstrates an abort, while the CVE record reports code execution.

CVSS severity7.8
High
EPSS probability1.05%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-buffer overflow in Creolabs Gravity 0.8.1 and earlier allows local users to execute code by compiling a crafted Gravity source file. During semantic analysis, gnode_function_add_upvalue reads two bytes four bytes beyond a heap allocation while resolving an identifier's captured upvalue. Exploitation requires a user to compile the crafted file; the public proof of concept demonstrates an abort, while the CVE record reports code execution.

The record

CVE
CVE-2021-32281
Published
Sep 20, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1204.002, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 20, 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1204.002Malicious File
T1203Exploitation for Client Execution

Public exploit references

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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