CVE-2021-3706Network attack vector

Session hijacking via JavaScript-readable persistent login cookie

Published Sep 15, 2021 · Updated Aug 3, 2024

Cookie protection flaw in Pi-hole AdminLTE before 5.6 allows attackers to read a reusable login cookie through same-origin scripts. In scripts/pi-hole/php/password.php, both cookie-setting paths omitted the HttpOnly argument to setcookie, exposing persistentlogin to JavaScript. Exploitation requires attacker-controlled script execution in the dashboard origin; theft of the stored password hash enables session impersonation.

CVSS severity7.5
High
EPSS probability1.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cookie protection flaw in Pi-hole AdminLTE before 5.6 allows attackers to read a reusable login cookie through same-origin scripts. In scripts/pi-hole/php/password.php, both cookie-setting paths omitted the HttpOnly argument to setcookie, exposing persistentlogin to JavaScript. Exploitation requires attacker-controlled script execution in the dashboard origin; theft of the stored password hash enables session impersonation.

The record

CVE
CVE-2021-3706
Published
Sep 15, 2021
Updated
Aug 3, 2024
Vendor
Pi-hole
Product
Pi-hole AdminLTE
Classifications
CWE-1004, CWE-732, T1539
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 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?

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

  1. Affected versionversion=unspecified <5.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Pi-hole · Pi-hole AdminLTEversion=unspecified <5.6

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.4huntr.devCVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
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 exploitUnconfirmed

Weakness, pattern, technique

CWE-1004Sensitive Cookie Without 'HttpOnly' Flag
CWE-732Incorrect Permission Assignment for Critical Resource
T1539Steal Web Session Cookie

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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