CVE-2020-10543Network attack vector

Heap buffer overflow via nested regex quantifiers

Published Jun 5, 2020 · Updated Aug 4, 2024

Heap-based buffer overflow in Perl before 5.30.3 allows attackers to corrupt memory by supplying a crafted regular expression. The regular expression compiler calculates storage for nested quantifiers without checking signed size_t multiplication and addition, underallocating the heap buffer before attacker-supplied data is written beyond it. Exposure requires an application to evaluate attacker-supplied regular expressions on a 32-bit system with enough memory for partial quantifier expansions.

CVSS severity8.2
High
EPSS probability11.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in Perl before 5.30.3 allows attackers to corrupt memory by supplying a crafted regular expression. The regular expression compiler calculates storage for nested quantifiers without checking signed size_t multiplication and addition, underallocating the heap buffer before attacker-supplied data is written beyond it. Exposure requires an application to evaluate attacker-supplied regular expressions on a 32-bit system with enough memory for partial quantifier expansions.

The record

CVE
CVE-2020-10543
Published
Jun 5, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 5, 2020CVE 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

6.4NIST NVDAV:N/AC:L/Au:N/C:N/I:P/A:P
8.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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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