CVE-2020-3537 | Cisco Jabber for Windows Universal Naming Convention Link Handling Vulnerability

A vulnerability in Cisco Jabber for Windows software could allow an authenticated, remote attacker to gain access to sensitive information. The vulnerability is due to improper validation of message contents. An attacker could exploit this vulnerability by sending specially crafted messages that contain Universal Naming Convention (UNC) links to a targeted user and convincing the user to follow the provided link. A successful exploit could allow the attacker to cause the application to access a remote system, possibly allowing the attacker to gain access to sensitive information that the attacker could use in additional attacks.

Published: 2020-09-03 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-3537 is rated Moderate Risk (46.7/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.27%). Review affected assets and schedule remediation.

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-2020-3537

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 2026-06-15 0.36% 1.27% +0.90%
2 2026-04-26 0.26% 0.36% +0.11%
3 2026-03-18 — 0.26% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-3537

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.7 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/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:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.1 3.6 [email protected]
5.7 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/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:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.1 3.6 [email protected]
3.5 2.0 LOW
AV:N/AC:M/Au:S/C:P/I:N/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:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 6.8 2.9 [email protected]

Weakness enumeration for CVE-2020-3537

Affected software / configurations for CVE-2020-3537

Vendor Product Version Raw CPE
cisco jabber >= 12.1, < 12.1.3 cpe:2.3:a:cisco:jabber:*:*:*:*:*:windows:*:*
cisco jabber >= 12.5, < 12.5.2 cpe:2.3:a:cisco:jabber:*:*:*:*:*:windows:*:*
cisco jabber >= 12.6, < 12.6.3 cpe:2.3:a:cisco:jabber:*:*:*:*:*:windows:*:*
cisco jabber >= 12.7, < 12.7.2 cpe:2.3:a:cisco:jabber:*:*:*:*:*:windows:*:*
cisco jabber >= 12.8, < 12.8.3 cpe:2.3:a:cisco:jabber:*:*:*:*:*:windows:*:*
cisco jabber >= 12.9, < 12.9.1 cpe:2.3:a:cisco:jabber:*:*:*:*:*:windows:*:*

References for CVE-2020-3537

cvelogic Threat Intelligence