CVE-2023-53957Public exploitNetwork attack vectorHinoki check available

Session hijacking via same-origin cookie-capture script

Published Dec 19, 2025 · Updated Dec 19, 2025

Session cookie exposure in Kimai 1.30.10 allows remote attackers to hijack user sessions after victims open attacker-planted PHP content. The proof-of-concept PHP reads the browser-supplied $_COOKIE array and writes it to PoC.txt, while Kimai configures the session cookie with SameSite=Lax. Exploitation requires a logged-in victim to visit PHP already placed under the Kimai origin, so the published artifact does not establish cross-site theft without prior server-write capability.

CVSS severity8.5
High
EPSS probability0.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Session cookie exposure in Kimai 1.30.10 allows remote attackers to hijack user sessions after victims open attacker-planted PHP content. The proof-of-concept PHP reads the browser-supplied $_COOKIE array and writes it to PoC.txt, while Kimai configures the session cookie with SameSite=Lax. Exploitation requires a logged-in victim to visit PHP already placed under the Kimai origin, so the published artifact does not establish cross-site theft without prior server-write capability.

The record

CVE
CVE-2023-53957
Published
Dec 19, 2025
Updated
Dec 19, 2025
Vendor
Kimai
Product
Kimai
Classifications
CWE-1275, T1539
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 19, 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=1.30.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Kimai · Kimaiversion=1.30.10

Published CVSS scores

8.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.5VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA: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-1275Sensitive Cookie with Improper SameSite Attribute
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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