CVE-2021-47256
5.5 · MEDIUMIn the Linux kernel, the following vulnerability has been resolved: mm/memory-failure: make sure wait for page writeback in memory_failure Our syzkaller trigger the "BUG_ON(!list_empty(&inode->i_…
Overview
CVE-2021-47256 is a medium-severity vulnerability. It was published on May 21, 2024 and has a CVSS 3.1 base score of 5.5 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical description
In the Linux kernel, the following vulnerability has been resolved:
mm/memory-failure: make sure wait for page writeback in memory_failure
Our syzkaller trigger the "BUG_ON(!list_empty(&inode->i_wb_list))" in
clear_inode:
kernel BUG at fs/inode.c:519!
Internal error: Oops - BUG: 0 [#1] SMP
Modules linked in:
Process syz-executor.0 (pid: 249, stack limit = 0x00000000a12409d7)
CPU: 1 PID: 249 Comm: syz-executor.0 Not tainted 4.19.95
Hardware name: linux,dummy-virt (DT)
pstate: 80000005 (Nzcv daif -PAN -UAO)
pc : clear_inode+0x280/0x2a8
lr : clear_inode+0x280/0x2a8
Call trace:
clear_inode+0x280/0x2a8
ext4_clear_inode+0x38/0xe8
ext4_free_inode+0x130/0xc68
ext4_evict_inode+0xb20/0xcb8
evict+0x1a8/0x3c0
iput+0x344/0x460
do_unlinkat+0x260/0x410
__arm64_sys_unlinkat+0x6c/0xc0
el0_svc_common+0xdc/0x3b0
el0_svc_handler+0xf8/0x160
el0_svc+0x10/0x218
Kernel panic - not syncing: Fatal exception
A crash dump of this problem show t
Remediation
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
References
How CyberStrike helps
Reason, not just scan
It reasons through your app's logic the way a human pentester would, so it finds flaws signature scanners miss.
Learn moreVerified findings
Every finding is proven exploitable before you see it, which cuts the false positives that bury real risk.
Learn moreAI-driven DAST and SAST
Probe running apps and read source from one engine, so issues are caught before and after they ship.
Learn moreOpen source
Read exactly how it tests and what it reports. CyberStrike is open source and in early access.
View the repo
Frequently asked questions
What is CVE-2021-47256?
CVE-2021-47256 is a medium-severity vulnerability. It was published on May 21, 2024 and has a CVSS 3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2021-47256?
This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2021-47256?
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-47256?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2021-47256 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.
Related MEDIUM CVEs from 2021
View all- 6.9CVE-2020-8101
Improper Neutralization of Special Elements used in a Command ('Command Injection') vulnerability in
View details - 6.9CVE-2021-21332
Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is
View details - 6.9CVE-2020-13603
Integer Overflow in memory allocating functions. Zephyr versions >= 1.14.2, >= 2.4.0 contain Integer
View details - 6.9CVE-2021-28556
Magento versions 2.4.2 (and earlier), 2.4.1-p1 (and earlier) and 2.3.6-p1 (and earlier) are affected
View details - 6.9CVE-2021-38517
Certain NETGEAR devices are affected by out-of-bounds reads and writes. This affects R6400 before 1.
View details - 6.9CVE-2021-38523
NETGEAR R6400 devices before 1.0.1.70 are affected by a stack-based buffer overflow by an authentica
View details - 6.9CVE-2021-37699
Next.js is an open source website development framework to be used with the React library. In affect
View details - 6.9CVE-2021-36841
Authenticated Stored Cross-Site Scripting (XSS) vulnerability in YITH Maintenance Mode (WordPress pl
View details - 6.9CVE-2021-36845
Multiple Authenticated Stored Cross-Site Scripting (XSS) vulnerabilities in YITH Maintenance Mode (W
View details - 6.9CVE-2021-38400
An attacker with physical access to Boston Scientific Zoom Latitude Model 3120 can remove the hard d
View details - 6.9CVE-2021-41174
Grafana is an open-source platform for monitoring and observability. In affected versions if an atta
View details - 6.9CVE-2021-34357
A cross-site scripting (XSS) vulnerability has been reported to affect QNAP device running QmailAgen
View details