Cyber Resilience

CVE-2025-62514

Crypto Weakness in Parsec.Cloud Parsec 3.0.0 – 3.6.0

Public PoCCrypto Weakness
Published
29 January 2026
Modified
02 March 2026
Patch / advisory
CVSS Score v3.1 8.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L
EPSS Score 0.0026 18th percentile
Risk Priority 60 floored blend · peak EPSS

Summary

CVE-2025-62514 is a high-severity Use of a Broken or Risky Cryptographic Algorithm (CWE-327) vulnerability in Parsec.Cloud Parsec. Its CVSS base score is 8.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Weaken Encryption (T1600); ranked at the 18th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SC-13 (Cryptographic Protection) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-62514 is a cryptographic vulnerability in Parsec, a cloud-based application for secure file sharing. It affects versions on the 3.x branch prior to 3.6.0, specifically the libparsec_crypto component when compiled with the RustCrypto backend. The flaw arises because libparsec_crypto does not validate for weak order points on the Curve25519 elliptic curve. Only the Parsec web application is impacted, as the desktop version uses the libsodium backend instead.

An attacker in a man-in-the-middle (MITM) position can exploit this during the Diffie-Hellman key exchange by supplying weak order points to both communicating parties. This leads to a high probability that both parties derive the identical shared key, which the attacker also knows. As a result, the Short Authenticated String (SAS) code exchange succeeds, falsely assuring both parties that no MITM is present and enabling the attacker to decrypt and potentially tamper with communications.

Parsec version 3.6.0 patches the issue by adding proper checks for weak order points in the RustCrypto backend, as detailed in the commit at https://github.com/Scille/parsec-cloud/commit/197bb6387b49fec872b5e4a04dcdb82b3d2995b2 and the security advisory at https://github.com/Scille/parsec-cloud/security/advisories/GHSA-hrc9-gm58-pgj9. Affected users should upgrade to 3.6.0 or later, with code references highlighting the fix in libparsec_crypto's private.rs and related curve25519-dalek dependencies.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Parsec is a cloud-based application for cryptographically secure file sharing. In versions on the 3.x branch prior to 3.6.0, `libparsec_crypto`, a component of the Parsec application, does not check for weak order point of Curve25519 when compiled with its RustCrypto…

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backend. In practice this means an attacker in a man-in-the-middle position would be able to provide weak order points to both parties in the Diffie-Hellman exchange, resulting in a high probability to for both parties to obtain the same shared key (hence leading to a successful SAS code exchange, misleading both parties into thinking no MITM has occurred) which is also known by the attacker. Note only Parsec web is impacted (as Parsec desktop uses `libparsec_crypto` with the libsodium backend). Version 3.6.0 of Parsec patches the issue.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1600 Weaken Encryption Defense Impairment
Adversaries may compromise a network device’s encryption capability in order to bypass encryption that would otherwise protect data communications.
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
T1040 Network Sniffing Credential Access
Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network.
T1600.001 Reduce Key Space Defense Impairment
Adversaries may reduce the level of effort required to decrypt data transmitted over the network by reducing the cipher strength of encrypted communications.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-22475Shared CWE-1240, CWE-327
CVE-2023-51392Shared CWE-1240, CWE-327
CVE-2024-37137Shared CWE-1240, CWE-327
CVE-2025-3938Shared CWE-327
CVE-2023-40696Shared CWE-327
CVE-2024-4765Shared CWE-327
CVE-2026-6412Shared CWE-327
CVE-2023-23040Shared CWE-327
CVE-2023-28509Shared CWE-327
CVE-2023-51839Shared CWE-327

Affected Assets

parsec.cloud
parsec
3.0.0 — 3.6.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 18 hardening rules · 8 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

SC-13 requires selection and implementation of specific cryptography types, directly stopping use of broken algorithms.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require use of approved, proven cryptographic implementations and forbid risky custom ones.

PR.DS-01 partial match
prevents

PR.DS-01 promotes encryption for data-at-rest but never requires strong algorithms, leaving CWE-327 fully possible; the weakness is also far broader than data-at-rest so one narrow control removes none of its total risk.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Mandating approved algorithms, cipher strength and usage standards directly stops the selection of broken or weak cryptographic primitives that attackers can exploit.

finds

Security testing can detect use of weak or non-compliant cryptographic primitives before deployment.

prevents

The explicit call-out of cryptography-related legal constraints (import/export, key escrow, digital-signature validity) reduces the likelihood that an organization will adopt broken or non-compliant cryptographic algorithms that violate those rules.

prevents

Access to current specialist guidance and early vulnerability alerts enables timely replacement of broken or risky cryptographic algorithms with stronger alternatives.

prevents

Secure SDLC requires vetted crypto libraries and standards, reducing risky custom implementations.

prevents

Application security requirements can specify approved cryptographic standards and disallow risky primitives.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248524 OL 8 must implement NIST FIPS-validated cryptography for the following: To provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. prevents CWE-1240, CWE-327
  • V-248534 OL 8 must employ FIPS 140-2 approved cryptographic hashing algorithms for all stored passwords. prevents CWE-1240
Oracle Linux 9 (1 rule)
  • V-271628 OL 9 must employ FIPS 140-3 approved cryptographic hashing algorithms for all stored passwords. prevents CWE-1240
RHEL 8 (2 rules)
  • V-230223 RHEL 8 must implement NIST FIPS-validated cryptography for the following: To provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. prevents CWE-1240
  • V-230224 All RHEL 8 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at rest protection. prevents CWE-1240
Windows 10 (1 rule)
  • V-220937 The system must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327
Windows 11 (1 rule)
  • V-253461 The system must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327
Windows Server 2016 (1 rule)
  • V-225053 Windows Server 2016 must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327
Windows Server 2019 (1 rule)
  • V-205654 Windows Server 2019 must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327
Windows Server 2022 (1 rule)
  • V-254474 Windows Server 2022 must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327

References