CVE-2021-33909

HIGH 7.8CVE-2021-33909 · Published 20/07/2021 · updated 17/06/2026

In short

CVE-2021-33909 is a HIGH (CVSS 7.8) vulnerability affecting communications session border controller (oracle).
Chance of exploitation in the next 30 days (EPSS): 9.7%, higher than 95.5% of all vulnerabilities.
No patched version is listed yet: follow the vendor's advisory in References.

Package	Affected versions	Patched versions
communications session border controller oracle	`= 8.2= 8.3= 8.4= 9.0`	No fix yet

Description

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.

References

packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesystem-Layer.html · Exploit
packetstormsecurity.com/files/163671/Kernel-Live-Patch-Security-Notice-LSN-0079-1.html · Third Party Advisory
packetstormsecurity.com/files/164155/Kernel-Live-Patch-Security-Notice-LSN-0081-1.html · Third Party Advisory
packetstormsecurity.com/files/165477/Kernel-Live-Patch-Security-Notice-LSN-0083-1.html · Third Party Advisory
openwall.com/lists/oss-security/2021/07/22/7 · Mailing List
openwall.com/lists/oss-security/2021/08/25/10 · Mailing List
openwall.com/lists/oss-security/2021/09/17/2 · Mailing List
openwall.com/lists/oss-security/2021/09/17/4 · Mailing List
openwall.com/lists/oss-security/2021/09/21/1 · Mailing List
cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.4

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