CVE-2021-1525 | Cisco Webex Meetings and Webex Meetings Server File Redirect Vulnerability

A vulnerability in Cisco Webex Meetings and Cisco Webex Meetings Server could allow an unauthenticated, remote attacker to redirect users to a malicious file. This vulnerability is due to improper validation of URL paths in the application interface. An attacker could exploit this vulnerability by persuading a user to follow a specially crafted URL that is designed to cause Cisco Webex Meetings to include a remote file in the web UI. A successful exploit could allow the attacker to cause the application to offer a remote file to a user, which could allow the attacker to conduct further phishing or spoofing attacks.

Published: 2021-06-04 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-1525 is rated Low Risk (31.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.17%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-1525

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-17 0.11% 0.17% +0.06%
2 2023-03-07 1.05% 0.11% -0.94%
3 2022-04-01 — 1.05% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-1525

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.7 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 1.4 [email protected]
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]
5.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 4.9 [email protected]

Weakness enumeration for CVE-2021-1525

Affected software / configurations for CVE-2021-1525

Vendor Product Version Raw CPE
cisco webex_meetings_online 41.3.5 cpe:2.3:a:cisco:webex_meetings_online:41.3.5:*:*:*:*:*:*:*
cisco webex_meetings_server < 3.0 cpe:2.3:a:cisco:webex_meetings_server:*:*:*:*:*:*:*:*
cisco webex_meetings_server 3.0 cpe:2.3:a:cisco:webex_meetings_server:3.0:-:*:*:*:*:*:*
cisco webex_meetings_server 3.0 cpe:2.3:a:cisco:webex_meetings_server:3.0:maintenance_release1:*:*:*:*:*:*
cisco webex_meetings_server 3.0 cpe:2.3:a:cisco:webex_meetings_server:3.0:maintenance_release2:*:*:*:*:*:*
cisco webex_meetings_server 3.0 cpe:2.3:a:cisco:webex_meetings_server:3.0:maintenance_release3:*:*:*:*:*:*
cisco webex_meetings_server 4.0 cpe:2.3:a:cisco:webex_meetings_server:4.0:-:*:*:*:*:*:*
cisco webex_meetings_server 4.0 cpe:2.3:a:cisco:webex_meetings_server:4.0:maintenance_release1:*:*:*:*:*:*
cisco webex_meetings_server 4.0 cpe:2.3:a:cisco:webex_meetings_server:4.0:maintenance_release2:*:*:*:*:*:*
cisco webex_meetings_server 4.0 cpe:2.3:a:cisco:webex_meetings_server:4.0:maintenance_release3:*:*:*:*:*:*
cisco webex_meetings_server 4.0 cpe:2.3:a:cisco:webex_meetings_server:4.0:maintenance_release3_security_patch3:*:*:*:*:*:*
cisco webex_meetings_server 4.0 cpe:2.3:a:cisco:webex_meetings_server:4.0:maintenance_release3_security_patch4:*:*:*:*:*:*

References for CVE-2021-1525

cvelogic Threat Intelligence