Description
ProFTPD before 1.3.9c and 1.3.10rc3 contains a heap-based buffer overflow vulnerability in the mod_sftp module that allows authenticated low-privilege attackers to achieve arbitrary code execution by sending crafted SFTP packet fragments exceeding the 16 KB reassembly buffer in the fxp.c component. Attackers can supply oversized fragments to trigger an incorrectly conditioned reallocation, corrupt pool freelist metadata, overwrite the root_fs BSS global pointer to reference a fake filesystem struct, and redirect pr_fsio_stat() to system() via a crafted RENAME request.
Affected products
proftpd: proftpd
References6
- github.com/proftpd/proftpd/commit/4ee8701bcf425f11b3b2116e634ff… Patch
- www.vulncheck.com/advisories/proftpd-mod-sftp-heap-buffer-overf… Third Party AdvisoryPatchRelease Notes
- github.com/proftpd/proftpd/blob/master/RELEASE_NOTES Release Notes
- github.com/proftpd/proftpd/issues/2190 Issue Tracking
- github.com/proftpd/proftpd/releases/tag/v1.3.10rc3-3 ProductRelease Notes
- github.com/proftpd/proftpd/releases/tag/v1.3.9c ProductRelease Notes
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 4.0
-
8.7
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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 - EPSS — exploit probability
- 1% percentile: 61 · as of 14 November 2026
- CWE
- CWE-122
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.