Vulnerability Monitor

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CVE-2021-33909

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.

Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.8, requiring local system access to exploit with relatively low complexity without requiring user interaction requiring only low-level privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 8 products from linux, from fedoraproject, from debian and 5 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2021-07-20T19:15:09.747

Last Modified

2024-11-21T06:09:45.353

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.8 (HIGH)

CVSSv2 Vector

AV:L/AC:L/Au:N/C:C/I:C/A:C

  • Access Vector: LOCAL
  • Access Complexity: LOW
  • Authentication: NONE
  • Confidentiality Impact: COMPLETE
  • Integrity Impact: COMPLETE
  • Availability Impact: COMPLETE
Exploitability Score

3.9

Impact Score

10.0

Weaknesses
  • Type: Primary
    CWE-190
    CWE-787
Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Operating System linux linux_kernel < 3.13 Yes
Operating System linux linux_kernel < 4.4.276 Yes
Operating System linux linux_kernel < 4.9.276 Yes
Operating System linux linux_kernel < 4.14.240 Yes
Operating System linux linux_kernel < 4.19.198 Yes
Operating System linux linux_kernel < 5.4.134 Yes
Operating System linux linux_kernel < 5.10.52 Yes
Operating System linux linux_kernel < 5.12.19 Yes
Operating System linux linux_kernel < 5.13.4 Yes
Operating System fedoraproject fedora 34 Yes
Operating System debian debian_linux 9.0 Yes
Operating System debian debian_linux 10.0 Yes
Application netapp hci_management_node - Yes
Application netapp solidfire - Yes
Application oracle communications_session_border_controller 8.2 Yes
Application oracle communications_session_border_controller 8.3 Yes
Application oracle communications_session_border_controller 8.4 Yes
Application oracle communications_session_border_controller 9.0 Yes
Operating System sonicwall sma1000_firmware ≤ 12.4.2-02044 Yes
Hardware sonicwall sma1000 - No
References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For linux's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.