CVE-2020-25705: 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 effec...

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

Metrics

CVSS 3.1

7.4/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS Probability

6.69%

93.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	< 5.10.0
Redhat	Enterprise Linux	7.0
Redhat	Enterprise Linux	8.0

References

Timeline

Published: Nov 17, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-25705?

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

How severe is CVE-2020-25705?

CVE-2020-25705 has a CVSS score of 7.4/10 (HIGH severity). The EPSS model estimates a 6.69% probability of exploitation in the next 30 days.

How do I fix CVE-2020-25705?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.