CVE-2021-42056

Exp

Thales Safenet Authentication Client (SAC) for Linux and Windows through 10.7.7 creates insecure temporary hid and lock files allowing a local attacker, through a symlink attack, to overwrite arbitrary files, and potentially achieve arbitrary command execution with high privileges.

Published: 2022-06-24 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-42056 is rated High Exploit Risk (60.4/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.97%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). 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-2021-42056

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

Exploit prediction scoring system (EPSS) score for CVE-2021-42056

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 2.34% 0.97% -1.37%
2 2025-11-21 1.44% 2.34% +0.90%
3 2025-11-18 1.44%

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-42056

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.7 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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.
0.8 5.9 [email protected]
7.2 2.0 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
3.9 10.0 [email protected]

Weakness enumeration for CVE-2021-42056

Affected software / configurations for CVE-2021-42056

Vendor Product Version Raw CPE
thalesgroup safenet_authentication_client <= 10.7.7 cpe:2.3:a:thalesgroup:safenet_authentication_client:*:*:*:*:*:*:*:*

References for CVE-2021-42056

URL Tags
https://github.com/z00z00z00/Safenet_SAC_CVE-2021-42056 Exploit Third Party Advisory
cvelogic Threat Intelligence