Review reviewHigh

CVE-2021-27365

cloud backup, linux kernel

An issue was discovered in the Linux kernel through 5.11.3. Certain iSCSI data structures do not have appropriate length constraints or checks, and can exceed the PAGE_SIZE value. An unprivileged user can send a Netlink message that is associated with iSCSI, and has a length up to the maximum length of a Netlink message.

CVSS
7.8
EPSS
2.08%
79.7% percentile
CISA KEV
Not listed
Published
2021.03.07
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability2.08%
Technical severityCVSS 7.8

Vulnerability overview

An issue was discovered in the Linux kernel through 5.11.3. Certain iSCSI data structures do not have appropriate length constraints or checks, and can exceed the PAGE_SIZE value. An unprivileged user can send a Netlink message that is associated with iSCSI, and has a length up to the maximum length of a Netlink message.

Affected product and versions

Product
cloud backup, linux kernel
Affected versions
< 4.4.260, >= 4.5 < 4.9.260, >= 4.10 < 4.14.224, >= 4.15 < 4.19.179, >= 4.20 < 5.4.103, >= 5.5 < 5.10.21, >= 5.11 < 5.11.4, 9.0, >= 7.4.0 <= 7.7.1
Fixed versions
4.4.260, 4.9.260, 4.14.224, 4.19.179, 5.4.103, 5.10.21, 5.11.4

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that cloud backup, linux kernel and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-787
CVE-2021-27365 — cloud backup, linux kernel | SECUFOCUS NOW