CryptoLib: Integer Underflow (Wrap or Wraparound)
CVE-2025-29909 is a critical-severity integer underflow (wrap or wraparound) vulnerability in CryptoLib from Nasa, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected CryptoLib versions: <= 1.3.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.08% chance of exploitation within 30 days, higher than 66% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of CryptoLib you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.9 | High | CNA (github.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official 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, a heap buffer overflow vulnerability in CryptoLib's `Crypto_TC_ApplySecurity()` allows an attacker to craft a malicious TC frame that causes out-of-bounds memory writes. This can result in denial of service (DoS) or, under certain conditions, remote code execution (RCE). Any application or system that relies on CryptoLib for Telecommand (TC) processing and does not strictly validate incoming TC frames is at risk. This includes satellite ground stations or mission control software where attackers can inject malformed frames. A patch is available at commit c7e8a8745ff4b5e9bd7e500e91358e86d5abedcc.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Integer Underflow (Wrap or Wraparound)
The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.
More Integer Underflow (Wrap or Wraparound) vulnerabilities (CWE-191)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
Other vulnerabilities in CryptoLib
- 8.7 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 8.2 High severity
- 7.3 High severity
Recent Integer Underflow (Wrap or Wraparound) vulnerabilities
- 9.1 Critical severity
- 7.1 High severity
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
Spotted an error? Tell us.