CVE-2021-1705Network attack vector

Remote code execution via memory corruption

Published Jan 12, 2021 · Updated Oct 8, 2024

Memory corruption in Microsoft Edge Legacy allows remote attackers to execute code when a user views a crafted webpage. The specific EdgeHTML object or parsing operation responsible has not been publicly disclosed. User interaction is required, and successful exploitation executes arbitrary code in the browser's user context.

CVSS severity7.5
High
EPSS probability1.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in Microsoft Edge Legacy allows remote attackers to execute code when a user views a crafted webpage. The specific EdgeHTML object or parsing operation responsible has not been publicly disclosed. User interaction is required, and successful exploitation executes arbitrary code in the browser's user context.

The record

CVE
CVE-2021-1705
Published
Jan 12, 2021
Updated
Oct 8, 2024
Vendor
Microsoft
Product
Microsoft Edge Legacy
Classifications
T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Oct 8, 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=1.0..0 <publication

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Edge Legacyversion=1.0..0 <publication

Published CVSS scores

4.2Microsoft CorporationCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
7.6NIST NVDAV:N/AC:H/Au:N/C:C/I:C/A:C

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 exploitUnconfirmed

Weakness, pattern, technique

T1189Drive-by Compromise

Public exploit references

No public exploit references are available in this record.

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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