CVE-2021-27365

Exp

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.

Published: 2021-03-07 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-27365 is rated High Exploit Risk (75.7/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.10%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.76% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-27365

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-27365

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.34% 2.10% +1.76%
2 2026-05-08 0.50% 0.34% -0.16%
3 2026-04-04 — 0.50% —

Full EPSS history (28 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-27365

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
4.6 2.0 MEDIUM
AV:L/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 3.9 6.4 [email protected]

Weakness enumeration for CVE-2021-27365

OS Trackers for CVE-2021-27365

vendor priority summary link
debian not yet assigned CVE-2021-27365 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-27365
redhat high — https://access.redhat.com/security/cve/CVE-2021-27365
suse high — https://www.suse.com/security/cve/CVE-2021-27365/
ubuntu high CVE-2021-27365 high priority: Ubuntu including 169 source packages (linux, linux-allwinner, …), 2181 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1696, not-affected 232, released 217, ignored 36. https://ubuntu.com/security/CVE-2021-27365

Affected software / configurations for CVE-2021-27365

Vendor Product Version Raw CPE
linux linux_kernel <= 5.11.3 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
oracle tekelec_platform_distribution >= 7.4.0, <= 7.7.1 cpe:2.3:a:oracle:tekelec_platform_distribution:*:*:*:*:*:*:*:*
netapp solidfire_baseboard_management_controller_firmware — cpe:2.3:o:netapp:solidfire_baseboard_management_controller_firmware:-:*:*:*:*:*:*:*

References for CVE-2021-27365

URL Tags
http://packetstormsecurity.com/files/162117/Kernel-Live-Patch-Security-Notice-LSN-0075-1.html Third Party Advisory VDB Entry
https://blog.grimm-co.com/2021/03/new-old-bugs-in-linux-kernel.html Exploit Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=1182715 Issue Tracking Third Party Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ec98ea7070e94cc25a422ec97d1421e28d97b7ee Mailing List Patch Vendor Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f9dbdf97a5bd92b1a49cee3d591b55b11fd7a6d5 Mailing List Patch Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/03/msg00035.html Mailing List Third Party Advisory
https://security.netapp.com/advisory/ntap-20210409-0001/ Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/03/06/1 Mailing List Third Party Advisory
https://www.oracle.com/security-alerts/cpuoct2021.html Patch Third Party Advisory
cvelogic Threat Intelligence