CVE-2021-45701

Memory disclosure via in-place state patching

Published Dec 26, 2021 · Updated Aug 4, 2024

Use-after-free in the tremor-script crate before 0.11.6 allows attackers to disclose freed memory through a crafted patch expression. The in-place patch optimization can retain borrowed event strings in state after the event's backing byte array is freed, exposing stale or reallocated memory. Exploitation requires a Tremor script to patch state with event-referenced keys or values and assign the result back to state.

CVSS severity9.8
Critical
EPSS probability1.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the tremor-script crate before 0.11.6 allows attackers to disclose freed memory through a crafted patch expression. The in-place patch optimization can retain borrowed event strings in state after the event's backing byte array is freed, exposing stale or reallocated memory. Exploitation requires a Tremor script to patch state with event-referenced keys or values and assign the result back to state.

The record

CVE
CVE-2021-45701
Published
Dec 26, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-416
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Dec 26, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/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.

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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)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free

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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