Buffer overflow in Brocade Fabric_operating_system
CVE-2021-22555
A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/x_tables.c. This allows an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space
Vulnerability class: Buffer Overflow
EPSS: 0.787 (99.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.
Affected products
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Public proof-of-concept exploits
References
- cve-coordination@google.com (Exploit, Third Party Advisory, x_refsource_MISC)
- cve-coordination@google.com (Patch, Mailing List, x_refsource_MISC, Vendor Advisory)
- cve-coordination@google.com (Patch, Mailing List, x_refsource_MISC, Vendor Advisory)
- cve-coordination@google.com (VDB Entry, Third Party Advisory, x_refsource_MISC)
- cve-coordination@google.com (x_refsource_CONFIRM, Third Party Advisory)
- cve-coordination@google.com (Exploit, VDB Entry, Third Party Advisory, x_refsource_MISC)
- cve-coordination@google.com (Exploit, VDB Entry, Third Party Advisory, x_refsource_MISC)
- cve-coordination@google.com (Exploit, VDB Entry, Third Party Advisory, x_refsource_MISC)
- cve-coordination@google.com (Exploit, VDB Entry, Third Party Advisory, x_refsource_MISC)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
Frequently asked questions
- What is CVE-2021-22555?
- CVE-2021-22555 is a high-severity vulnerability in Brocade Fabric_operating_system, classified under Out-of-bounds Write. CVSS score: 8.3/10. Published 2021-07-07.
- How severe is CVE-2021-22555?
- High severity. CVSS v3 base score is 8.3 out of 10.
- Is CVE-2021-22555 known to be exploited?
- Yes. CVE-2021-22555 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-10-06), indicating it is being actively exploited. 124 public proof-of-concept repositories are indexed.