Authentication bypass via loose cookie hash comparison
Published Nov 13, 2022 · Updated Nov 3, 2025
Authentication bypass in NagVis 1.9.33 and earlier allows remote attackers to gain authenticated access by forging a session cookie. CoreLogonMultisite::checkAuthCookie uses PHP's loose inequality operator to compare the supplied cookie hash with a calculated SHA-256 digest, so a zeroed hash matches a numeric 0e-form digest. Exploitation requires repeated unauthenticated guesses until a matching digest occurs; the upstream test required 58,191,275 attempts.
Summary
What happened
Authentication bypass in NagVis 1.9.33 and earlier allows remote attackers to gain authenticated access by forging a session cookie. CoreLogonMultisite::checkAuthCookie uses PHP's loose inequality operator to compare the supplied cookie hash with a calculated SHA-256 digest, so a zeroed hash matches a numeric 0e-form digest. Exploitation requires repeated unauthenticated guesses until a matching digest occurs; the upstream test required 58,191,275 attempts.
The record
- CVE
- CVE-2022-3979
- Published
- Nov 13, 2022
- Updated
- Nov 3, 2025
- Vendor
- NagVis Project
- Product
- NagVis
- Classifications
- CWE-704, T1550.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 13, 2022CVE publishedPublication date reported by the CVE source.
- Nov 3, 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.
- Affected versionversion=1.9.0
- Affected versionversion=1.9.1
- Affected versionversion=1.9.10
- Affected versionversion=1.9.11
- Affected versionversion=1.9.12
- Affected versionversion=1.9.13
- Affected versionversion=1.9.14
- Affected versionversion=1.9.15
- Affected versionversion=1.9.16
- Affected versionversion=1.9.17
- Affected versionversion=1.9.18
- Affected versionversion=1.9.19
- Affected versionversion=1.9.2
- Affected versionversion=1.9.20
- Affected versionversion=1.9.21
- Affected versionversion=1.9.22
- Affected versionversion=1.9.23
- Affected versionversion=1.9.24
- Affected versionversion=1.9.25
- Affected versionversion=1.9.26
- Affected versionversion=1.9.27
- Affected versionversion=1.9.28
- Affected versionversion=1.9.29
- Affected versionversion=1.9.3
- Affected versionversion=1.9.30
- Affected versionversion=1.9.31
- Affected versionversion=1.9.32
- Affected versionversion=1.9.33
- Affected versionversion=1.9.4
- Affected versionversion=1.9.5
- Affected versionversion=1.9.6
- Affected versionversion=1.9.7
- Affected versionversion=1.9.8
- Affected versionversion=1.9.9
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- Zeroed cookie-hash proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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