What’s Vulnerable › Vulnerabilities

CVE-2020-26147

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 7.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-05-11 · updated 2026-06-17

Description

An issue was discovered in the Linux kernel 5.8.9. The WEP, WPA, WPA2, and WPA3 implementations reassemble fragments even though some of them were sent in plaintext. This vulnerability can be abused to inject packets and/or exfiltrate selected fragments when another device sends fragmented frames and the WEP, CCMP, or GCMP data-confidentiality protocol is used.

Affected products

• Arista C-65 Firmware: all versions
• Arista C-75 Firmware: all versions
• Arista O-90 Firmware: all versions
• Arista W-68 Firmware: all versions
• Debian Linux: 9.0
• Linux kernel: from 4.4 before 4.4.271; from 4.9 before 4.9.271; from 4.14 before 4.14.235; from 4.19 before 4.19.193; from 5.4 before 5.4.124; from 5.10 before 5.10.42 — fixed in 4.14.235, 4.19.193, 4.4.271, 4.9.271, 5.10.42, 5.12.9
• Siemens Scalance W1700 Ieee 802.11Ac Firmware: all versions
• Siemens Scalance W700 Ieee 802.11N Firmware: all versions

How to fix

Upgrade to a fixed version: Linux kernel 4.14.235, 4.19.193, 4.4.271, 4.9.271. Check the vendor advisory for mitigations.

References

• http://www.openwall.com/lists/oss-security/2021/05/11/12
• https://cert-portal.siemens.com/productcert/pdf/ssa-913875.pdf
• https://github.com/vanhoefm/fragattacks/blob/master/SUMMARY.md
• https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html
• https://lists.debian.org/debian-lts-announce/2021/06/msg00020.html
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wifi-faf-22epcEWu
• https://www.arista.com/en/support/advisories-notices/security-advisories/12602-security-advisory-63
• https://www.fragattacks.com
• http://www.openwall.com/lists/oss-security/2021/05/11/12
• https://cert-portal.siemens.com/productcert/pdf/ssa-913875.pdf
• https://github.com/vanhoefm/fragattacks/blob/master/SUMMARY.md
• https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html

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