CVE-2020-27969Public exploitNetwork attack vector

Address-bar spoofing via stopped cross-origin navigation

Published Sep 13, 2021 · Updated Aug 4, 2024

Origin validation errors in Yandex Browser for Android before 20.8.4 allow remote attackers to spoof the address bar and bypass SOP. A crafted page opens a trusted URL in a named window, reuses that window for another origin, stops navigation, and writes attacker-controlled content while the trusted address remains displayed. A victim must open the attacker's page and activate its script; successful exploitation can misrepresent malicious content as a trusted site and expose cross-origin data.

CVSS severity7.3
High
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Origin validation errors in Yandex Browser for Android before 20.8.4 allow remote attackers to spoof the address bar and bypass SOP. A crafted page opens a trusted URL in a named window, reuses that window for another origin, stops navigation, and writes attacker-controlled content while the trusted address remains displayed. A victim must open the attacker's page and activate its script; successful exploitation can misrepresent malicious content as a trusted site and expose cross-origin data.

The record

CVE
CVE-2020-27969
Published
Sep 13, 2021
Updated
Aug 4, 2024
Vendor
Yandex
Product
Yandex Browser
Classifications
CWE-346, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 13, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=All versions prior to version 20.8.4.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Yandex · Yandex Browserversion=All versions prior to version 20.8.4.

Published CVSS scores

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
7.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

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-346Origin Validation Error
T1189Drive-by Compromise

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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