Uncontrolled Recursion in xen (Alpine package)



Risk Low
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2020-29566
CWE-ID CWE-674
Exploitation vector Local
Public exploit N/A
Vulnerable software
 IBM Systems Director
Server applications / Other server solutions

xen (Alpine package)
Operating systems & Components / Operating system package or component

Vendor IBM Corporation
Alpine Linux Development Team

Security Bulletin

This security bulletin contains one low risk vulnerability.

1) Uncontrolled Recursion

EUVDB-ID: #VU49137

Risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-29566

CWE-ID: CWE-674 - Uncontrolled Recursion

Exploit availability: No

Description

The vulnerability allows a local authenticated user to perform a denial of service (DoS) attack.

An issue was discovered in Xen through 4.14.x. When they require assistance from the device model, x86 HVM guests must be temporarily de-scheduled. The device model will signal Xen when it has completed its operation, via an event channel, so that the relevant vCPU is rescheduled. If the device model were to signal Xen without having actually completed the operation, the de-schedule / re-schedule cycle would repeat. If, in addition, Xen is resignalled very quickly, the re-schedule may occur before the de-schedule was fully complete, triggering a shortcut. This potentially repeating process uses ordinary recursive function calls, and thus could result in a stack overflow. A malicious or buggy stubdomain serving a HVM guest can cause Xen to crash, resulting in a Denial of Service (DoS) to the entire host. Only x86 systems are affected. Arm systems are not affected. Only x86 stubdomains serving HVM guests can exploit the vulnerability.

Mitigation

Install update from vendor's website.

Vulnerable software versions

IBM Systems Director: 6.3.2.2

xen (Alpine package): 1.42

xen (Alpine package): 1.1.7-0ubuntu1 - 1.2.3-0ubuntu2.7

xen (Alpine package): 3.0.8-1 - 3.0.13-1

xen (Alpine package): 2:1.3.2-2ubuntu0.1

xen (Alpine package): 1:6.2.3-5

xen (Alpine package): 0.11-4

xen (Alpine package): 3.2.21-1

xen (Alpine package): 1.88-1

xen (Alpine package): 0.2.3.2-1

xen (Alpine package): 0.101 - 0.102ubuntu1

xen (Alpine package): 0.1.0-0ubuntu1 - 0.1.5-0ubuntu1

xen (Alpine package): 3.1-1 - 3.1-2

xen (Alpine package): 1.3.1-1 - 1.3.1-2

xen (Alpine package): 3.1-1

xen (Alpine package): 0.18.1.1-9ubuntu1

xen (Alpine package): 4.63-15

xen (Alpine package): 3.1.6.1-1

xen (Alpine package): 2.55-2 - 2.72-1

xen (Alpine package): 2.2.0.3-2ubuntu5

xen (Alpine package): 3.5.11.2003.06.04-3

xen (Alpine package): 5.4-2ubuntu1

xen (Alpine package): 5.4b-1

xen (Alpine package): 0.15

xen (Alpine package): 0.18ubuntu0.2 - 0.32

xen (Alpine package): 0.3.6.0amd12 - 1.12.9

xen (Alpine package): 1.9.9-3 - 1.9.10-1

xen (Alpine package): 0.48-4

xen (Alpine package): 0.9b-20040421-1 - 1.1-20120215-2

xen (Alpine package): 0.16 - 0.35

xen (Alpine package): 0.2 - 0.9

xen (Alpine package): 0.4

xen (Alpine package): 2.5.3 - 2.17.5ubuntu1

xen (Alpine package): 3.4.0-1

xen (Alpine package): 0.14-1 - 0.15-2

xen (Alpine package): 2014.1-3

xen (Alpine package): 24.0-0ubuntu1

xen (Alpine package): 0.5.2-0ubuntu1 - 1.2.5ubuntu1daily13.06.14-0ubuntu1

xen (Alpine package): 3.0-0ubuntu1

xen (Alpine package): 1.5.2 - 1.6.2

xen (Alpine package): 0.1.8 - 1.0.75

xen (Alpine package): 1.20.0 - 2.18.2

xen (Alpine package): 20081029ubuntu63 - 20101020ubuntu468

xen (Alpine package): 0.74 - 9.20160115

xen (Alpine package): 0.2.12 - 1.5.49

xen (Alpine package): 1.8.8-2ubuntu1

xen (Alpine package): 0.2.8-8 - 0.2.11-1

xen (Alpine package): 0.3 - 1.8.42

xen (Alpine package): 5.3.28-3 - 5.3.28-4

xen (Alpine package): 1.5

xen (Alpine package): 0.4.5 - 0.5.8-2.2

xen (Alpine package): 0.2.11-1build1

xen (Alpine package): 0.63

xen (Alpine package): 0.3.1-0ubuntu1 - 0.10.0-3

xen (Alpine package): 0.13-1 - 0.22.1-2

xen (Alpine package): 2.1.0-2 - 2.1.26.dfsg1-14

xen (Alpine package): 0.5.16-3.5ubuntu1 - 0.5.17-6

xen (Alpine package): 1.3-1 - 1.3-3

xen (Alpine package): 5.11-1 - 7.35.0-1

xen (Alpine package): 1.3.9-17 - 2.0.3-2

xen (Alpine package): 0.1.2-1 - 0.2.6-1ubuntu1

xen (Alpine package): 1.0.47-2 - 1.0.64-0ubuntu1

xen (Alpine package): 2.1-3-dfsg-1 - 2.1-3-dfsg-2

xen (Alpine package): 0.100-3

xen (Alpine package): 2:1.0.6-2ubuntu7 - 2:1.6.4-1

xen (Alpine package): 0.8 - 9ubuntu2

xen (Alpine package): 3.0pl1-50 - 3.0pl1-119

xen (Alpine package): 1.0.0-0ubuntu1 - 1.0.0-0ubuntu2

xen (Alpine package): expression - 7.1.1-1

xen (Alpine package): 2.8.13-7 - 2.8.13-10

xen (Alpine package): 2.4.2-16 - 2.7-1

xen (Alpine package): 0.92-0ubuntu3 - 0.98-1

xen (Alpine package): 4.5.7-1 - 8.20-3ubuntu4

xen (Alpine package): 0.2.10-3 - 0.4.6-3

xen (Alpine package): 1.5 - 1.141

xen (Alpine package): 1:0.8.6-0ubuntu4 - 1:0.9.7.6-0ubuntu2

xen (Alpine package): 0.3ubuntu7 - 0.3ubuntu15.2

xen (Alpine package): 1.2.12-1ubuntu1 - 1.2.12-1

xen (Alpine package): 0.7-svn20050721 - 1.4.29-1

xen (Alpine package): 2.8.12.1-1.6 - 3.9.0-1

xen (Alpine package): 1.0.5-2 - 1.0.8-3

xen (Alpine package): 0.25-0ubuntu1 - 0.25-0ubuntu3

xen (Alpine package): 0.9-0ubuntu1 - 0.12-0ubuntu1

xen (Alpine package): 1.4.4

xen (Alpine package): 2.2.15-1

xen (Alpine package): 1.4.2

xen (Alpine package): 4.8.9

xen (Alpine package): 3.0.4

xen (Alpine package): 2.1.0

xen (Alpine package): 1.4.17

xen (Alpine package): 2.2.0b2

xen (Alpine package): r12.0 nil

xen (Alpine package): 3.0

xen (Alpine package):

xen (Alpine package): before 4.14.1-r0

CPE2.3 External links

https://git.alpinelinux.org/aports/commit/?id=1f5fe5eb0e0bb4588f6b1b8b4e1563293acbb087


Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.



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