CVE-2021-45841

Exp

In Terramaster F4-210, F2-210 TOS 4.2.X (4.2.15-2107141517), an attacker can self-sign session cookies by knowing the target's MAC address and the user's password hash. Guest users (disabled by default) can be abused using a null/empty hash and allow an unauthenticated attacker to login as guest.

Published: 2022-04-25 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-45841 is rated High Exploit Risk (86.8/100): CVSS High severity, with high exploitation likelihood (EPSS 65.51%, 98th percentile). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +17.98% over the last day, indicating growing attacker interest. Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2021-45841

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-45841

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 2025-11-21 47.53% 65.51% +17.98%
2 2025-11-18 65.51% 47.53% -17.98%
3 2025-10-02 65.51%

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-45841

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
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.
2.2 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P 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:P)
Partial availability impact.
8.6 6.4 [email protected]

Weakness enumeration for CVE-2021-45841

Affected software / configurations for CVE-2021-45841

Vendor Product Version Raw CPE
terra-master tos 4.2.15-2107141517 cpe:2.3:o:terra-master:tos:4.2.15-2107141517:*:*:*:*:*:*:*

References for CVE-2021-45841

cvelogic Threat Intelligence