CVE-2021-33909

moderate-risk

Published 2021-07-20

fs/seq_file.c in the Linux kernel 3.16 through 5.13.x before 5.13.4 does not properly restrict seq buffer allocations, leading to an integer overflow, an Out-of-bounds Write, and escalation to root by an unprivileged user, aka CID-8cae8cd89f05.

Do I need to act?

2.2% chance of exploitation in next 30 days

EPSS score — moderate exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 7.8/10 High

LOCAL / LOW complexity

Affected Products (11)

Linux Kernel

Fedora

Debian Linux

Hci Management Node

Solidfire

Communications Session Border Controller

Sma1000 Firmware

Affected Vendors

Debian Linux Oracle Sonicwall Fedoraproject Netapp

References (40)

Exploit http://packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesy...

Third Party Advisory http://packetstormsecurity.com/files/163671/Kernel-Live-Patch-Security-Notice-LS...

Third Party Advisory http://packetstormsecurity.com/files/164155/Kernel-Live-Patch-Security-Notice-LS...

Third Party Advisory http://packetstormsecurity.com/files/165477/Kernel-Live-Patch-Security-Notice-LS...

Mailing List http://www.openwall.com/lists/oss-security/2021/07/22/7

Mailing List http://www.openwall.com/lists/oss-security/2021/08/25/10

Mailing List http://www.openwall.com/lists/oss-security/2021/09/17/2

Mailing List http://www.openwall.com/lists/oss-security/2021/09/17/4

Mailing List http://www.openwall.com/lists/oss-security/2021/09/21/1

Mailing List https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.4

Patch https://github.com/torvalds/linux/commit/8cae8cd89f05f6de223d63e6d15e31c8ba9cf53...

Mailing List https://lists.debian.org/debian-lts-announce/2021/07/msg00014.html

Mailing List https://lists.debian.org/debian-lts-announce/2021/07/msg00015.html

Mailing List https://lists.debian.org/debian-lts-announce/2021/07/msg00016.html

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro...

Third Party Advisory https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2022-0015

Third Party Advisory https://security.netapp.com/advisory/ntap-20210819-0004/

Third Party Advisory https://www.debian.org/security/2021/dsa-4941

Exploit https://www.openwall.com/lists/oss-security/2021/07/20/1

Patch https://www.oracle.com/security-alerts/cpujan2022.html

and 20 more references

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moderate-risk

Severity 24/34 · High

Exploitability 5/34 · Minimal

Exposure 16/34 · Moderate