ComSndFTP v1.3.7 Beta USER Format String RCE
Published Aug 13, 2025
9.3
CRITICALCVSS 4.0
EPSS 1.64%
Description
ComSndFTP FTP Server version 1.3.7 Beta contains a format string vulnerability in its handling of the USER command. By sending a specially crafted username containing format specifiers, a remote attacker can overwrite a hardcoded function pointer in memory (specifically WSACleanup from Ws2_32.dll). This allows the attacker to redirect execution flow and bypass DEP protections using a ROP chain, ultimately leading to arbitrary code execution. The vulnerability is exploitable without authentication and affects default configurations.
Affected products
-
- Version 1.3.7 BetaStatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| ComSndFTP | FTP Server | n/a |
|
No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
1 other source (NVD) ▾
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/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
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
PoCAutomatable
YesTechnical Impact
TotalDecision
n/aAssessed Aug 14, 2025 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2025–2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (7 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.64% (0.01643) | 75.56th | v5 (v2026.06.15) |
| Jun 15, 2026 | 1.99% (0.01993) | 78.02th | v5 (v2026.06.15) |
| Jun 9, 2026 | 72.59% (0.72586) | 98.78th | v4 (v2025.03.14) |
| Jan 9, 2026 | 59.71% (0.59713) | 98.18th | v4 (v2025.03.14) |
| Dec 13, 2025 | 67.80% (0.67801) | 98.51th | v4 (v2025.03.14) |
| Oct 8, 2025 | 64.45% (0.64451) | 98.35th | v4 (v2025.03.14) |
| Aug 14, 2025 | 0.41% (0.00406) | 60.25th | v4 (v2025.03.14) |
References (5)
- https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/windows/ftp/comsnd_ftpd_fmtstr.rb exploit
- https://web.archive.org/web/20120317214524/http://ftp.comsnd.com/ product
- https://www.exploit-db.com/exploits/19024 exploit
- https://www.exploit-db.com/exploits/19177 exploit
- https://www.vulncheck.com/advisories/comsndftp-user-format-string-rce third-party-advisory
Change history (0)
No recorded changes yet.