What’s Vulnerable › Vulnerabilities

CVE-2020-25705

• Severity: high (CVSS 7.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 6.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-11-17 · updated 2026-06-17
• Weakness: CWE-330

Description

A flaw in ICMP packets in the Linux kernel may allow an attacker to quickly scan open UDP ports. This flaw allows an off-path remote attacker to effectively bypass source port UDP randomization. Software that relies on UDP source port randomization are indirectly affected as well on the Linux Based Products (RUGGEDCOM RM1224: All versions between v5.0 and v6.4, SCALANCE M-800: All versions between v5.0 and v6.4, SCALANCE S615: All versions between v5.0 and v6.4, SCALANCE SC-600: All versions prior to v2.1.3, SCALANCE W1750D: v8.3.0.1, v8.6.0, and v8.7.0, SIMATIC Cloud Connect 7: All versions, SIMATIC MV500 Family: All versions, SIMATIC NET CP 1243-1 (incl. SIPLUS variants): Versions 3.1.39 and later, SIMATIC NET CP 1243-7 LTE EU: Version

Affected products

• Linux kernel: before 5.10.0 — fixed in 5.10.0
• Red Hat Enterprise Linux: 7.0, 8.0

How to fix

Upgrade to a fixed version: Linux kernel 5.10.0. Check the vendor advisory for mitigations.

References

• https://us-cert.cisa.gov/ics/advisories/icsa-21-131-03
• https://us-cert.cisa.gov/ics/advisories/icsa-21-131-03

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