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Mentions the CVE; no further detail.
CVE-2021-27860 KEVPublic exploit High · 8.8 EPSS 39.7%
FatPipe WARP, IPVPN, and MPVPN Configuration Upload exploit
FatPipe · WARP, IPVPN, and MPVPN software
Summary
The FatPipe WARP, IPVPN, and MPVPN software has an unrestricted file upload flaw (CWE-434) in its web management interface. A remote attacker with no authentication and no privileges can upload a file to any location on the filesystem, but this requires a user to interact with the attack (per the vector's UI:R component).
Official description · NVD
A vulnerability in the web management interface of FatPipe WARP, IPVPN, and MPVPN software prior to versions 10.1.2r60p92 and 10.2.2r44p1 allows a remote, unauthenticated attacker to upload a file to any location on the filesystem. The FatPipe advisory identifier for this vulnerability is FPSA006.
Priority scorePatchfirst’s 0 to 100 ranking. It adds points for CISA KEV listing, ransomware use, EPSS, threat reports, public exploit code and CVSS. Every CVE page shows the breakdown. Breakdown
72.8 / 100
- Exploited
- Yes, in CISA KEV
- Reports
- 1
- Tactics
- 1/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited 33 days after disclosure.
- Disclosedday 0
CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
1 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order 1PersistenceTA0003
Web Shell T1505.003
MITRE CTID mapping of the KEV entry · primary impact
CVE-2021-27860 is a vulnerability in the web management interface in FatPipe software. The vulnerability allowed APT actors to gain access to an unrestricted file upload function to drop a webshell for exploitation activity with root access, leading to elevated privileges and potential follow-on activity. Exploitation of this vulnerability then served as a jumping off point into other infrastructure for the APT actors.
Lower-confidence links (1)
These come from early or generic mappings, text matching, or contradict this CVE’s details (for example a public-facing technique on a bug that needs a user to open a file). Shown for completeness.
- Exploit Public-Facing ApplicationT1190 needs user interaction; not a public-facing exploit
Detection
0 rules for this CVE · 35 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2021-27860 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
Web ShellT1505.00335 general rules
- Certificate Request Export to Exchange Webservercriticaltest
- CVE-2021-40539 Zoho ManageEngine ADSelfService Plus Exploitcriticaltest
- Mailbox Export to Exchange Webservercriticaltest
- Oracle WebLogic Exploitcriticaltest
- Solarwinds SUPERNOVA Webshell Accesscriticaltest
- Webshell Remote Command Executioncriticaltest
- WordPress Wp2shell Webshell Plugin Accesscriticalexperimental
- Antivirus - Web Shell Detection Signaturehightest
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Named in 1 threat report1 reportmedia.defense.gov
Reports are matched by finding the exact id CVE-2021-27860 in their text; nobody has reviewed the match. One passage is shown per report, at most 320 characters, linked to the original.
Also mentioned in 50 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Actively_Exploited_Kev | Oct 29, 202628 Oct 2026
- Actively_Exploited_Kev | Oct 28, 202627 Oct 2026
- Actively_Exploited_Kev | Oct 27, 202626 Oct 2026
- Actively_Exploited_Kev | Oct 24, 202623 Oct 2026
- Actively_Exploited_Kev | Oct 23, 202622 Oct 2026
- Actively_Exploited_Kev | Oct 22, 202621 Oct 2026
- 44 more on OTX