Listen to this Post
How the CVE Works
The vulnerability in py-libp2p (before v0.2.3) allows an attacker to exploit the RSA key-handling mechanism. When a peer sends an excessively large RSA key during a handshake, the library fails to properly validate or limit the key size. This leads to excessive CPU and memory consumption while processing the key, resulting in a Denial of Service (DoS) condition. The lack of size restrictions or early termination in key parsing allows an attacker to exhaust system resources, disrupting service availability.
DailyCVE Form
Platform: py-libp2p
Version: < 0.2.3
Vulnerability: DoS via RSA key
Severity: Moderate
Date: Jul 14, 2025
Prediction: Patch by Aug 2025
What Undercode Say
Check installed version pip show py-libp2p Mitigation (temporary): Restrict peer RSA key sizes in config LIBP2P_RSA_MAX_BITS=4096
How Exploit
1. Attacker crafts oversized RSA key.
2. Sends key during peer handshake.
3. Victim system stalls parsing key.
Protection from this CVE
- Upgrade to py-libp2p ≥ 0.2.3.
- Enforce RSA key size limits.
- Monitor peer resource usage.
Impact
- Service disruption.
- Resource exhaustion.
- Unstable node performance.
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
