CVE-2021-28857Public exploitNetwork attack vector

Credential disclosure via exposed cookie contents

Published Jun 15, 2021 · Updated Aug 3, 2024

Credential disclosure in TP-Link TL-WPA4220 firmware 4.0.2 Build 20180308 Rel.37064 allows remote attackers to obtain login credentials. The management interface places both the username and password in an HTTP cookie instead of limiting the cookie to a non-credential session token. Exploitation requires access to an issued cookie; disclosure exposes reusable device-management credentials.

CVSS severity7.5
High
EPSS probability1.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Credential disclosure in TP-Link TL-WPA4220 firmware 4.0.2 Build 20180308 Rel.37064 allows remote attackers to obtain login credentials. The management interface places both the username and password in an HTTP cookie instead of limiting the cookie to a non-credential session token. Exploitation requires access to an issued cookie; disclosure exposes reusable device-management credentials.

The record

CVE
CVE-2021-28857
Published
Jun 15, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-522, T1539
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 15, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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-522Insufficiently Protected Credentials
T1539Steal Web Session Cookie

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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