SFTP root escape via component-agnostic prefix check in ssh_sftpd (Erlang OTP)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.38 % · percentile 32 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- EEF
- NVD status
- Modified
Description
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Erlang OTP (ssh_sftpd module) allows Path Traversal. This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl and program routines ssh_sftpd:is_within_root/2. The SFTP server uses string prefix matching via lists:prefix/2 rather than proper path component validation when checking if a path is within the configured root directory. This allows authenticated users to access sibling directories that share a common name prefix with the configured root directory. For example, if root is set to /home/user1, paths like /home/user10 or /home/user1_backup would incorrectly be considered within the root. This issue affects OTP from OTP 17.0 before OTPÂ 28.4.1, OTPÂ 27.3.4.9 and OTPÂ 26.2.5.18, corresponding to ssh from 3.0.1 before 5.5.1, 5.2.11.6 and 5.1.4.14.
Weaknesses (CWE)
- CWE-22 — Improper Limitation of a Pathname to a Restricted Directory
References
- https://github.com/erlang/otp/security/advisories/GHSA-4749-w85x-hw9h
- https://cna.erlef.org/cves/CVE-2026-23942.html
- https://osv.dev/vulnerability/EEF-CVE-2026-23942
- https://www.erlang.org/doc/system/versions.html#order-of-versions
- https://github.com/erlang/otp/commit/27688a824f753d4c16371dc70e88753fb410590b
- https://github.com/erlang/otp/commit/9e0ac85d3485e7898e0da88a14be0ee2310a3b28
- https://github.com/erlang/otp/commit/5ed603a1211b83b8be2d1fc06d3f3bf30c3c9759
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | MEDIUM 5.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N | EEF |
| CVSS 4.0 | MEDIUM 5.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/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 | NVD · 6b3ad84c-e1a6-4bf7-a703-f496b71e49db (Secondary) |
| CVSS 3.1 | MEDIUM 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2026-11778
- GCVE · GCVE-0-2026-23942
CERT-FR advisories
- CERTFR-2026-AVI-0436 — Multiples vulnérabilités dans Tenable Identity Exposure · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0321 — Multiples vulnérabilités dans les produits Microsoft · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:*≥ 17.0 < 26.2.5.18cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:*≥ 27.0 < 27.3.4.9cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:*≥ 28.0 < 28.4.1cpe:2.3:a:erlang:erlang\/ssh:*:*:*:*:*:*:*:*≥ 3.0.1 < 5.1.4.14cpe:2.3:a:erlang:erlang\/ssh:*:*:*:*:*:*:*:*≥ 5.2 < 5.2.11.6cpe:2.3:a:erlang:erlang\/ssh:*:*:*:*:*:*:*:*≥ 5.5 ≤ 5.5.1
Affected products
| Product | Versions |
|---|---|
| Erlang · OTP | affected 3.0.1 < * |
| Erlang · OTP | affected 17.0 < * ; affected 84adefa331c4159d432d22840663c38f155cd4c1 < * |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |