CVE-2023-29547Public exploitNetwork attack vector

Cookie spoofing via insecure document.cookie overwrite

Published Jun 2, 2023 · Updated Jan 10, 2025

Cookie spoofing in Mozilla Firefox, Firefox for Android, and Firefox Focus for Android before 112 allows attackers to alter cookie values. The document.cookie setter in an insecure-origin process accepts a same-name insecure cookie even when the cookie jar retains an existing Secure cookie, leaving script-visible state out of sync. The attack requires a same-site script or network position and can make an application trust an attacker-controlled cookie value that is not sent in HTTP requests.

CVSS severity6.5
Medium
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cookie spoofing in Mozilla Firefox, Firefox for Android, and Firefox Focus for Android before 112 allows attackers to alter cookie values. The document.cookie setter in an insecure-origin process accepts a same-name insecure cookie even when the cookie jar retains an existing Secure cookie, leaving script-visible state out of sync. The attack requires a same-site script or network position and can make an application trust an attacker-controlled cookie value that is not sent in HTTP requests.

The record

CVE
CVE-2023-29547
Published
Jun 2, 2023
Updated
Jan 10, 2025
Vendor
Mozilla
Product
Firefox
Classifications
Unavailable
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 2, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 10, 2025Record 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 <112

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <112
Mozilla · Firefox for Androidversion=unspecified <112
Mozilla · Firefox Focus for Androidversion=unspecified <112

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/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.

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

No sourced classifications are available.

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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