Vulnerability Name:

CVE-2020-8223 (CCN-189305)

Assigned:2020-07-16
Published:2020-07-16
Updated:2022-01-01
Summary:A logic error in Nextcloud Server 19.0.0 caused a privilege escalation allowing malicious users to reshare with higher permissions than they got assigned themselves.
CVSS v3 Severity:6.5 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N)
5.7 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): Required
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): High
Availibility (A): None
5.5 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L)
4.8 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): Required
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): Low
Integrity (I): Low
Availibility (A): Low
CVSS v2 Severity:3.5 Low (CVSS v2 Vector: AV:N/AC:M/Au:S/C:N/I:P/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Medium
Authentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): None
Integrity (I): Partial
Availibility (A): None
6.5 Medium (CCN CVSS v2 Vector: AV:N/AC:L/Au:S/C:P/I:P/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): Partial
Integrity (I): Partial
Availibility (A): Partial
Vulnerability Type:CWE-269
Vulnerability Consequences:Gain Privileges
References:Source: MITRE
Type: CNA
CVE-2020-8223

Source: XF
Type: UNKNOWN
nextcloud-cve20208223-priv-esc(189305)

Source: MISC
Type: Exploit, Third Party Advisory
https://hackerone.com/reports/889243

Source: FEDORA
Type: Mailing List, Third Party Advisory
FEDORA-2020-c9863904de

Source: FEDORA
Type: Mailing List, Third Party Advisory
FEDORA-2020-050aaa14f7

Source: CCN
Type: NC-SA-2020-029
Re-Sharing allows increase of privileges

Source: MISC
Type: Vendor Advisory
https://nextcloud.com/security/advisory/?id=NC-SA-2020-029

Vulnerable Configuration:Configuration 1:
  • cpe:/a:nextcloud:nextcloud_server:19.0.0:-:*:*:*:*:*:*

    • Configuration 2:
  • cpe:/o:fedoraproject:fedora:32:*:*:*:*:*:*:*
  • OR cpe:/o:fedoraproject:fedora:33:*:*:*:*:*:*:*

    • Configuration CCN 1:
  • cpe:/a:nextcloud:nextcloud_server:18.0.0:-:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    BACK
    nextcloud nextcloud server 19.0.0 -
    fedoraproject fedora 32
    fedoraproject fedora 33
    nextcloud nextcloud server 18.0.0 -