What is CVE-2021-28715?

CVE-2021-28715 is a Medium severity Linux kernel vulnerability with a CVSS score of 6.5 out of 10. CVE-2021-28715 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-28715?

CVE-2021-28715 has a CVSS score of 6.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H.

Is there a patch available for CVE-2021-28715?

No patch is currently available for CVE-2021-28715. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2021-28715 actively exploited?

CVE-2021-28715 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2021-28715

Medium

Guest can force Linux netback driver to hog large amounts of kernel memory T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Incoming data packets for a guest in the Linux kernel's netback driver are buffered until the guest is ready to process them. There are some measures taken for avoiding to pile up too much data, but those can be bypassed by the guest: There is a timeout how long the client side of an interface can stop consuming new packets before it is assumed to have stalled, but this timeout is rather long (60 seconds by default). Using a UDP connection on a fast interface can easily accumulate gigabytes of data in that time. (CVE-2021-28715) The timeout could even never trigger if the guest manages to have only one free slot in its RX queue ring page and the next package would require more than one free slot, which may be the case when using GSO, XDP, or software hashing. (CVE-2021-28714)

Package Linux Kernel

Published 2022-01-06

Last modified 2025-05-22

CVSS version 3.1

Patch available

Awaiting data

CVSS 3.1 score

6.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

Low

Integrity

None

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Weakness type

CWE-770

CVE-2021-28715 is classified as CWE-770

See CWE-770 on MITRE CWE for full details on this weakness type.

References

The following references provide additional information about CVE-2021-28715 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Debian Security
https://lists.debian.org/debian-lts-announce/2022/03/msg00011.html

Mailing List Third Party Advisory
Debian Security
https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html

Mailing List Third Party Advisory
Debian Security
https://www.debian.org/security/2022/dsa-5050

Third Party Advisory
Debian Security
https://www.debian.org/security/2022/dsa-5096

Third Party Advisory
Xenbits
https://xenbits.xenproject.org/xsa/advisory-392.txt

Vendor Advisory

Details

CVE ID CVE-2021-28715

Severity Medium

CVSS score 6.5 / 10

CVSS version 3.1

Published 2022-01-06

Modified 2025-05-22

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2021-28715?

CVE-2021-28715 is a Medium severity Linux kernel vulnerability with a CVSS score of 6.5 out of 10 . CVE-2021-28715 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-28715?

CVE-2021-28715 has a CVSS score of 6.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H.
Is there a patch available for CVE-2021-28715?

No patch is currently available for CVE-2021-28715. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2021-28715 actively exploited?

No — CVE-2021-28715 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.