Security readout for executives and security teams
Plain-English summary
This is a critical flaw in FatPipe network edge software. An unauthenticated remote attacker could upload files through the web management interface and place them anywhere on the device filesystem. That creates realistic risk of full device compromise, service disruption, and follow-on access through network infrastructure.
Executive priority
Treat this as urgent for any exposed FatPipe appliance. It affects edge network infrastructure, requires no attacker credentials, and is listed by CISA as known exploited.
Technical view
CVE-2021-27860 is CWE-434 arbitrary file upload in FatPipe WARP, IPVPN, and MPVPN web management interfaces before 10.1.2r60p92 and 10.2.2r44p1. It is network-reachable, low complexity, needs no credentials or user interaction, and has CVSS 9.8.
Likely exposure
Exposure is most likely where FatPipe WARP, IPVPN, or MPVPN 10.1 or 10.2 management interfaces are reachable by untrusted networks and have not been upgraded to the fixed releases.
Exploitation context
Active exploitation is supported by CISA KEV inclusion. The source bundle also includes an IC3/FBI reference, but the provided text does not detail attacker tooling, scale, or current campaign status.
Researcher notes
Evidence supports arbitrary filesystem upload via the web management interface and fixed FatPipe versions. The bundle does not provide exploit mechanics, indicators of compromise, or detailed patch notes, so validation should stay focused on exposure, version state, and compromise review.
Mitigation direction
- Upgrade affected FatPipe systems to 10.1.2r60p92, 10.2.2r44p1, or later.
- Review FatPipe advisory FPSA006 and CISA KEV guidance for vendor-specific actions.
- Restrict web management interface access to trusted administrative networks where possible.
- Hunt affected appliances for suspicious files, configuration changes, and abnormal management access.
- Prioritize replacement or isolation if an affected appliance cannot be upgraded promptly.
Validation and detection
- Inventory FatPipe WARP, IPVPN, and MPVPN appliances and record exact software versions.
- Confirm whether the web management interface is reachable from the Internet or untrusted networks.
- Verify patched versions are 10.1.2r60p92, 10.2.2r44p1, or later.
- Review management logs and filesystem changes for unexplained uploads or modifications.
- Check CISA KEV tracking for organizational remediation deadlines and status.
Public sources used
Michael Williams reviewed this cited source version on .
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-434: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-27860 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.fatpipeinc.com/support/cve-list.phpCVE reference
- https://www.ic3.gov/Media/News/2021/211117-2.pdfCVE reference
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27860CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Unrestricted Upload of File with Dangerous Type
Unrestricted Upload of File with Dangerous Type represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.