CVE-2018-16495

In VOS user session identifier (authentication token) is issued to the browser prior to authentication but is not changed after the user successfully logs into the application. Failing to issue a new session ID following a successful login introduces the possibility for an attacker to set up a trap session on the device the victim is likely to login with.

Published: 2021-05-26 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-16495 is rated Moderate Risk (55.1/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.91%). 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-2018-16495

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 0.30% 0.91% +0.61%
2 2025-03-30 0.59% 0.30% -0.28%
3 2025-03-29 — 0.59% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-16495

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H 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:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]
6.5 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.0 6.4 [email protected]

Weakness enumeration for CVE-2018-16495

Affected software / configurations for CVE-2018-16495

Vendor Product Version Raw CPE
versa-networks versa_operating_system < 16.1r2s11 cpe:2.3:o:versa-networks:versa_operating_system:*:*:*:*:*:*:*:*
versa-networks versa_operating_system >= 20.2.0, < 20.2.2 cpe:2.3:o:versa-networks:versa_operating_system:*:*:*:*:*:*:*:*
versa-networks versa_operating_system >= 21.1.0, < 21.1.1 cpe:2.3:o:versa-networks:versa_operating_system:*:*:*:*:*:*:*:*

References for CVE-2018-16495

URL Tags
https://hackerone.com/reports/1168192 Third Party Advisory
cvelogic Threat Intelligence