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nextcloudNextcloudGHSA-JF3H-XF4Q-MH89
HistoryMar 09, 2022 - 6:52 a.m.

High memory usage for generating preview of broken image

2022-03-0906:52:40
github.com
27
denial of service
specially crafted files
nextcloud server
upgrade
disable preview generation
hackerone
pull request
support ticket

CVSS2

4.3

Attack Vector

NETWORK

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

PARTIAL

AV:N/AC:M/Au:N/C:N/I:N/A:P

CVSS3

6.5

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

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

EPSS

0.002

Percentile

64.5%

Description

Impact

An attacker can cause a denial of service by uploading specially crafted files which will cause the server to allocate too much memory / CPU.

Patches

It is recommended that the Nextcloud Server is upgraded to 21.0.8 , 22.2.4 or 23.0.1.

Workarounds

Disable preview generation with the 'enable_previews' config flag.

References

For more information

If you have any questions or comments about this advisory:

CVSS2

4.3

Attack Vector

NETWORK

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

PARTIAL

AV:N/AC:M/Au:N/C:N/I:N/A:P

CVSS3

6.5

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

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

EPSS

0.002

Percentile

64.5%