Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-27856

43
FAUCET Score

CVE-2021-27856 describes a critical vulnerability in FatPipe WARP, IPVPN, and MPVPN software versions prior to 10.1.2r60p91 and 10.2.2r42, where an administrative "cmuser" account exists without a password. This allows unauthenticated attackers to gain full control over affected devices. The vulnerability carries a CVSS score of 9.8 (Critical) due to its network-based attack vector, low complexity, and complete compromise of confidentiality, integrity, and availability. While not listed on the KEV catalog, exploit code is available via Nuclei templates, though there is no evidence of active exploitation or significant community discussion.

Impacted Technologies

VendorProductVersion(s)CPE
5.2.0CPE matchmatch criteria
cpe:2.3:o:fatpipeinc:ipvpn_firmware:5.2.0:r34:*:*:*:*:*:*
6.1.2CPE matchmatch criteria
cpe:2.3:o:fatpipeinc:ipvpn_firmware:6.1.2:r70p26:*:*:*:*:*:*
6.1.2CPE matchmatch criteria
cpe:2.3:o:fatpipeinc:ipvpn_firmware:6.1.2:r70p45-m:*:*:*:*:*:*
6.1.2CPE matchmatch criteria
cpe:2.3:o:fatpipeinc:ipvpn_firmware:6.1.2:r70p75-m:*:*:*:*:*:*
7.1.2CPE matchmatch criteria
cpe:2.3:o:fatpipeinc:ipvpn_firmware:7.1.2:r39:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

9.8CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
5.60%
Probability of exploitation in next 30 days
EPSS Percentile
92.1%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
Nuclei: CVE-2021-27856 · Oct 5, 2025
This CVE's current EPSS score of 0.0560 is in the 86th percentile among its peer group of 36,897 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

fatpipeinc.com / support/cve-list.php
Vendor Advisory
zeroscience.mk / codes/fatpipe_backdoor.txt
Third Party Advisory
zeroscience.mk / en/vulnerabilities/ZSL-2021-5684.php
Third Party Advisory