CVE-2025-45766
Executive Summary
CVE-2025-45766 is a disputed vulnerability reported in the Poco C++ library (version 1.14.1-release). The original claim asserts that the library implements weak encryption, but this has been contested on the grounds that key lengths are expected to be set by the application, not the library itself. The dispute is under review by CNA rules. No EPSS score, exploit code, or public proof-of-concept has been released. The vulnerability is not related to any specific package ecosystem (NPM, PyPI, Go, Ruby), so no supply chain section is included.
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CVSS Breakdown & Threat Level
- CVSS Score: 0.0 (Unscored due to dispute)
- Vector: UNKNOWN
- Threat Level: Low (disputed, no exploit available)
- EPSS Probability: 0.0% (extremely low exploitation likelihood)
Deep Dive & Mechanics
The Poco library (POCO C++ Libraries) provides networking, cryptography, and utility functions. The alleged weakness involves the encryption implementation, specifically that the library may use insufficient key lengths or weak algorithms by default. However, the dispute argues that the library correctly delegates key length decisions to the application developer, and that the library itself does not enforce weak settings. Without a confirmed vulnerability or patch, the mechanics remain theoretical. The CVE record is under dispute, meaning the validity is not yet settled.
Vulnerable vs. Patched Code
No specific vulnerable or patched code has been released. The dispute centers on whether the library’s default encryption behavior is a flaw or by design. No patch exists because the vendor (Poco) and the reporter disagree on the issue.
Exploitation & Lab Setup
Red Team
No exploit code is available. If the vulnerability were real, an attacker might attempt to downgrade encryption or force weak key lengths. However, without a public PoC, exploitation is not feasible.
Blue Team
Monitor for unusual encryption downgrade attempts or use of weak cipher suites in applications using Poco. Ensure applications explicitly set strong key lengths and algorithms.
Indicators of Compromise (IOCs)
No specific IOCs are available due to the disputed nature and lack of exploit.
Detection Engineering
YARA Rule
rule CVE_2025_45766_Poco_Weak_Encryption {
meta:
description = "Detects Poco library version 1.14.1-release with potential weak encryption"
author = "Valters IT"
date = "2025-04-10"
reference = "CVE-2025-45766"
strings:
$poco_version = "1.14.1-release"
$weak_cipher = "RC4" nocase
$short_key = "keylen" nocase
condition:
$poco_version and ($weak_cipher or $short_key)
}
Sigma Rule
title: Potential Weak Encryption in Poco Library
id: cve-2025-45766
status: experimental
description: Detects use of weak encryption algorithms or short key lengths in Poco library
logsource:
product: application
service: general
detection:
selection:
- "RC4"
- "keylen"
condition: selection
falsepositives:
- Legitimate use of weak ciphers in controlled environments
level: low
Suricata Rule
alert tcp any any -> any any (msg:"CVE-2025-45766 Poco Weak Encryption Attempt"; flow:to_server; content:"RC4"; nocase; sid:1000001; rev:1;)
Remediation & Mitigation
- Immediate: Review application code using Poco to ensure explicit strong encryption settings (e.g., AES-256, key lengths >= 256 bits).
- Long-term: Monitor the CVE dispute resolution. If confirmed, update Poco to a patched version or switch to a different cryptography library.
- Workaround: Do not rely on Poco’s default encryption settings; always specify algorithms and key lengths in application code.
Valters IT