Cyber Resilience

CVE-2025-27776

SSRF in Applio ≤ 3.2.7

Published
19 March 2025
Modified
01 August 2025
Patch / advisory
CVSS Score v4 8.8
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0053 42th percentile
Risk Priority 50 floored blend · peak EPSS

Summary

CVE-2025-27776 is a high-severity SSRF (CWE-918) vulnerability in Applio Applio. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 42th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — 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.

Applio, an open-source voice conversion tool, is affected by a server-side request forgery vulnerability combined with arbitrary file write in versions 3.2.7 and earlier. The issues reside in model_download.py at line 240 and are reachable through the Flask routes that handle model downloads. The blind SSRF permits outbound requests from the Applio server, while the file-write primitive permits creation of arbitrary files on the host filesystem; both are tracked under CWE-918.

An unauthenticated remote attacker can supply crafted inputs to trigger these primitives. The SSRF can be used to scan or interact with internal services reachable by the Applio host, and when paired with the related arbitrary-file-read issue CVE-2025-27784 it becomes a full SSRF capable of retrieving internal content. The file-write capability can further be chained with other flaws such as unsafe deserialization to obtain remote code execution on the Applio server.

Public references, including the GitHub Security Lab advisory GHSL-2024-341, confirm that no patches were available at the time of disclosure. The listed code locations in routes.py, model_download.py, and download.py illustrate the affected request-handling paths, and administrators are advised to restrict network egress and input sources until fixes are released.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Applio is a voice conversion tool. Versions 3.2.7 and prior are vulnerable to server-side request forgery (SSRF) and file write in `model_download.py` (line 240 in 3.2.7). The blind SSRF allows for sending requests on behalf of Applio server and can…

more

be leveraged to probe for other vulnerabilities on the server itself or on other back-end systems on the internal network, that the Applio server can reach. The blind SSRF can also be coupled with the arbitrary file read CVE-2025-27784 to read files from hosts on the internal network, that the Applio server can reach, which would make it a full SSRF. The file write allows for writing files on the server, which can be coupled with other vulnerabilities, for example an unsafe deserialization, to achieve remote code execution on the Applio server. As of time of publication, no known patches are available.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-27775Same product: Applio Applio
CVE-2025-27774Same product: Applio Applio
CVE-2025-27777Same product: Applio Applio
CVE-2025-27782Same product: Applio Applio
CVE-2025-27786Same product: Applio Applio
CVE-2025-27783Same product: Applio Applio
CVE-2025-27779Same product: Applio Applio
CVE-2025-27780Same product: Applio Applio
CVE-2025-27778Same product: Applio Applio
CVE-2025-27781Same product: Applio Applio

Affected Assets

applio
applio
≤ 3.2.7

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.3.6
  • V1.5.3
  • V5.3.2
  • V10.4.7

Mitigating Controls (NIST 800-53 r5) AI

Information flow enforcement can restrict which destinations the server is allowed to contact on behalf of users.

Input validation directly stops untrusted URLs from being accepted and fetched without destination checks.

Boundary protection limits the network reach of server-initiated requests even if SSRF occurs.

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 development practices directly include input validation and destination allow-listing that prevent SSRF.

DE.CM-09 partial match
prevents

Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover and record SSRF flaws in web applications.

PR.IR-01 partial match
prevents

Network segmentation and egress controls can limit the damage from successful SSRF requests.

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

Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.

References