How severe is CVE-2021-45841?

CVE-2021-45841 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-45841 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 8% (94th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-45841?

CVE-2021-45841 affects Terra-master Tos. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-45841?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-45841 published?

CVE-2021-45841 was published on 2022-04-25 and last updated on 2026-06-17.

CVE-2021-45841

CVE-2021-45841 is a high-severity vulnerability in Terra-master Tos with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 6.8
EPSS exploit prediction: 8% (94th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Terra-master Tos
Published: 2022-04-25
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-45841?: 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.
How severe is CVE-2021-45841?: CVE-2021-45841 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-45841 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 8% (94th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-45841?: CVE-2021-45841 affects Terra-master Tos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-45841?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-45841 published?: CVE-2021-45841 was published on 2022-04-25 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:terra-master:tos:4.2.15-2107141517:*:*:*:*:*:*:*

More vulnerabilities in Terra-master Tos

CVE-2021-45840 — Critical (CVSS 9.8): It is possible to execute arbitrary commands as root in Terramaster F4-210, F2-210 TOS 4.2.X (4.2.15-2107141517) by…
CVE-2021-45837 — Critical (CVSS 9.8): It is possible to execute arbitrary commands as root in Terramaster F4-210, F2-210 TOS 4.2.X (4.2.15-2107141517) by…
CVE-2020-15568 — Critical (CVSS 9.8): TerraMaster TOS before 4.1.29 has Invalid Parameter Checking that leads to code injection as root. This is a dynamic…
CVE-2020-28188 — Critical (CVSS 9.8): Remote Command Execution (RCE) vulnerability in TerraMaster TOS <= 4.2.06 allow remote unauthenticated attackers to…
CVE-2020-28187 — Critical (CVSS 9.8): Multiple directory traversal vulnerabilities in TerraMaster TOS <= 4.2.06 allow remote authenticated attackers to read,…
CVE-2021-45836 — High (CVSS 8.8): An authenticated attacker can execute arbitrary commands as root in Terramaster F4-210, F2-210 TOS 4.2.X…

All CVEs affecting Terra-master Tos →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

Browse all CWE-287 (Improper Authentication) vulnerabilities →