CVE-2020-23323Public exploitNetwork attack vector

Engine crash via unterminated Unicode escape

Published Jun 10, 2021 · Updated Aug 4, 2024

Heap out-of-bounds access in JerryScript 2.2.0 allows attackers to crash the engine with a truncated Unicode regular expression. The re_parse_char_escape routine in re-parser.c reads beyond the heap buffer because Unicode-mode parsing omits end-of-string checks before consuming escape characters. Execution requires an application to pass attacker-controlled JavaScript containing the malformed RegExp to an ES2015 Unicode-enabled JerryScript engine.

CVSS severity9.8
Critical
EPSS probability1.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap out-of-bounds access in JerryScript 2.2.0 allows attackers to crash the engine with a truncated Unicode regular expression. The re_parse_char_escape routine in re-parser.c reads beyond the heap buffer because Unicode-mode parsing omits end-of-string checks before consuming escape characters. Execution requires an application to pass attacker-controlled JavaScript containing the malformed RegExp to an ES2015 Unicode-enabled JerryScript engine.

The record

CVE
CVE-2020-23323
Published
Jun 10, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 10, 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 vectornetwork
Required privilegesunauthenticated

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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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