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CVE-2020-29569

HIGHCVSS 8.8/10EPSS 0.39%

Last modified

CVE-2020-29569 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped. EPSS estimates a 0.39% chance of exploitation in the next 30 days.

Description

An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped. However, the handler may not have time to run if the frontend quickly toggles between the states connect and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. Privilege escalation and information leaks cannot be ruled out. This only affects systems with a Linux blkback.

Metrics

CVSS 3.1
8.8/10

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

EPSS Probability
0.39%

30.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
XenXen<= 4.14.1
LinuxLinux Kernel>= 4.1.44, < 4.2
LinuxLinux Kernel>= 4.4.80, < 4.4.254
LinuxLinux Kernel>= 4.9.36, < 4.9.249
LinuxLinux Kernel>= 4.11.9, < 4.12
LinuxLinux Kernel>= 4.12, < 4.14.213
LinuxLinux Kernel>= 4.15, < 4.19.164
LinuxLinux Kernel>= 4.20, < 5.4.86
LinuxLinux Kernel>= 5.5, < 5.10.4
NetappHci Compute Node BiosAll versions
NetappSolidfire \& Hci Management NodeAll versions
NetappSolidfire \& Hci Storage NodeAll versions
DebianDebian Linux9.0
DebianDebian Linux10.0

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2020-29569?
An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped. However, the handler may not have time to run if the frontend quickly toggles between the states connect and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. Privilege escalation and information leaks cannot be ruled out. This only affects systems with a Linux blkback.
How severe is CVE-2020-29569?
CVE-2020-29569 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.39% probability of exploitation in the next 30 days.
How do I fix CVE-2020-29569?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-29569?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST