CVE-2020-16042Public exploitNetwork attack vector

Process-memory disclosure via uncleared BigInt overflow digit

Published Jan 8, 2021 · Updated Aug 4, 2024

Uninitialized memory use in V8 in Google Chrome before 87.0.4280.88 allows remote attackers to read process memory via crafted HTML. During a zero-offset BigInt right shift, MutableBigInt::RightShiftByAbsolute allocates an overflow digit but leaves it uncleared. A user must open attacker-controlled HTML; the demonstrated result is disclosure of prior process-memory contents, not code execution or data modification.

CVSS severity6.5
Medium
EPSS probability0.89%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uninitialized memory use in V8 in Google Chrome before 87.0.4280.88 allows remote attackers to read process memory via crafted HTML. During a zero-offset BigInt right shift, MutableBigInt::RightShiftByAbsolute allocates an overflow digit but leaves it uncleared. A user must open attacker-controlled HTML; the demonstrated result is disclosure of prior process-memory contents, not code execution or data modification.

The record

CVE
CVE-2020-16042
Published
Jan 8, 2021
Updated
Aug 4, 2024
Vendor
Google Cloud
Product
Google Chrome
Classifications
CWE-908, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 8, 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?

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

  1. Affected versionversion=unspecified <87.0.4280.88

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google Cloud · Google Chromeversion=unspecified <87.0.4280.88

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:P/I:N/A:N
6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-908Use of Uninitialized Resource
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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