Multiple vulnerabilities in Nextcloud Server
| Risk | Low |
| Patch available | YES |
| Number of vulnerabilities | 2 |
| CVE-ID | CVE-2021-22878 CVE-2021-22877 |
| CWE-ID | CWE-79 CWE-284 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software Subscribe |
Nextcloud Server Client/Desktop applications / Messaging software |
| Vendor |
Security Bulletin
This security bulletin contains information about 2 vulnerabilities.
1) Cross-site scripting
EUVDB-ID: #VU51011
Risk: Low
CVSSv3.1: 5.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-22878
CWE-ID:
CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Exploit availability: No
DescriptionThe disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data when renaming malicious file. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
MitigationInstall updates from vendor's website.
Vulnerable software versionsNextcloud Server: before 20.0.6
External linkshttp://nextcloud.com/security/advisory/?id=NC-SA-2021-005
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) Improper access control
EUVDB-ID: #VU51013
Risk: Low
CVSSv3.1: 7.6 [CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-22877
CWE-ID:
CWE-284 - Improper Access Control
Exploit availability: No
DescriptionThe vulnerability allows a remote user to gain unauthorized access to otherwise restricted functionality.
The vulnerability exists due to improper access restrictions. A remote administrator can populate own credentials for other users external storage configuration when they did not configure one yet.
MitigationInstall updates from vendor's website.
Vulnerable software versionsNextcloud Server: before 20.0.6
External linkshttp://nextcloud.com/security/advisory/?id=NC-SA-2021-004
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
