CVE intelligence and bounded remediation

CVE-2021-28038 — An issue was discovered in the Linux kernel through 5.11.3, as used with Xen PV

Medium CVSS 6.5

An issue was discovered in the Linux kernel through 5.11.3, as used with Xen PV. A certain part of the netback driver lacks necessary treatment of errors such as failed memory allocations (as a result of changes to the handling of grant mapping errors). A host OS denial of service may occur during misbehavior of a networking frontend driver. NOTE: this issue exists because of an incomplete fix for CVE-2021-26931.

Severity
Medium
CVSS
6.5 (3.1)
Published
2021-03-05
CISA KEV
Not currently listed
Ecosystem
linux/kernel
Weaknesses
CWE-770

Affected products

  • linux / linux_kernel
  • linux / linux_kernel / 5.12
  • debian / debian_linux / 9.0
  • netapp / cloud_backup
  • netapp / solidfire_baseboard_management_controller_firmware

Showing 5 representative product identities from 12 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

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