{"id":"CVE-2026-32147","state":"PUBLISHED","title":"SFTP chroot bypass via path traversal in SSH_FXP_FSETSTAT","description":"Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Erlang OTP ssh (ssh_sftpd module) allows an authenticated SFTP user to modify file attributes outside the configured chroot directory.\n\nThe SFTP daemon (ssh_sftpd) stores the raw, user-supplied path in file handles instead of the chroot-resolved path. When SSH_FXP_FSETSTAT is issued on such a handle, file attributes (permissions, ownership, timestamps) are modified on the real filesystem path, bypassing the root directory boundary entirely.\n\nAny authenticated SFTP user on a server configured with the root option can modify file attributes of files outside the intended chroot boundary. The prerequisite is that a target file must exist on the real filesystem at the same relative path. Note that this vulnerability only allows modification of file attributes; file contents cannot be read or altered through this attack vector.\n\nIf the SSH daemon runs as root, this enables direct privilege escalation: an attacker can set the setuid bit on any binary, change ownership of sensitive files, or make system configuration world-writable.\n\nThis vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl and program routines ssh_sftpd:do_open/4 and ssh_sftpd:handle_op/4.\n\nThis issue affects OTP from OTP 17.0 before OTP 28.4.3, OTP 27.3.4.11 and OTP 26.2.5.20, corresponding to ssh from 3.0.1 before 5.5.3, 5.2.11.7 and 5.1.4.15.","publishedAt":"2026-04-21T12:01:20.350Z","updatedAt":"2026-07-24T14:14:17.633Z","severity":{"score":5.3,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N","source":"EEF"},"assigner":"EEF","products":["Erlang OTP"],"affected":[{"vendor":"Erlang","product":"OTP","packageName":"ssh","packageURL":"pkg:otp/ssh?repository_url=https:%2F%2Fgithub.com%2Ferlang%2Fotp&vcs_url=git%20https:%2F%2Fgithub.com%2Ferlang%2Fotp.git","defaultStatus":"unknown","versions":[{"version":"3.01","status":"affected","lessThan":"*","changes":[{"at":"5.5.3","status":"unaffected"},{"at":"5.2.11.7","status":"unaffected"},{"at":"5.1.4.15","status":"unaffected"}],"versionType":"otp"}],"cpes":["cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"],"modules":["ssh_sftpd"],"programFiles":["src/ssh_sftpd.erl"],"programRoutines":[{"name":"ssh_sftpd:do_open/4"},{"name":"ssh_sftpd:handle_op/4"}],"repo":"https://github.com/erlang/otp"},{"vendor":"Erlang","product":"OTP","packageName":"erlang/otp","packageURL":"pkg:github/erlang/otp","defaultStatus":"unknown","versions":[{"version":"17.0","status":"affected","lessThan":"*","changes":[{"at":"28.4.3","status":"unaffected"},{"at":"27.3.4.11","status":"unaffected"},{"at":"26.2.5.20","status":"unaffected"}],"versionType":"otp"},{"version":"07b8f441ca711f9812fad9e9115bab3c3aa92f79","status":"affected","lessThan":"*","changes":[{"at":"28c5d5a6c5f873dc701b597276271763e7d1c004","status":"unaffected"}],"versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"],"modules":["ssh_sftpd"],"programFiles":["lib/ssh/src/ssh_sftpd.erl"],"programRoutines":[{"name":"ssh_sftpd:do_open/4"},{"name":"ssh_sftpd:handle_op/4"}],"repo":"https://github.com/erlang/otp"}],"references":["https://github.com/erlang/otp/security/advisories/GHSA-28jg-mw9x-hpm5","https://cna.erlef.org/cves/CVE-2026-32147.html","https://osv.dev/vulnerability/EEF-CVE-2026-32147","https://www.erlang.org/doc/system/versions.html#order-of-versions","https://github.com/erlang/otp/commit/28c5d5a6c5f873dc701b597276271763e7d1c004"],"weaknesses":["CWE-22"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/32xxx/CVE-2026-32147.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-32147","state":"PUBLISHED","datePublished":"2026-04-21T12:01:20.350Z","dateUpdated":"2026-07-24T14:14:17.633Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-03-10T22:37:29.213Z"},"containers":{"cna":{"title":"SFTP chroot bypass via path traversal in SSH_FXP_FSETSTAT","descriptions":[{"lang":"en","value":"Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Erlang OTP ssh (ssh_sftpd module) allows an authenticated SFTP user to modify file attributes outside the configured chroot directory.\n\nThe SFTP daemon (ssh_sftpd) stores the raw, user-supplied path in file handles instead of the chroot-resolved path. When SSH_FXP_FSETSTAT is issued on such a handle, file attributes (permissions, ownership, timestamps) are modified on the real filesystem path, bypassing the root directory boundary entirely.\n\nAny authenticated SFTP user on a server configured with the root option can modify file attributes of files outside the intended chroot boundary. The prerequisite is that a target file must exist on the real filesystem at the same relative path. Note that this vulnerability only allows modification of file attributes; file contents cannot be read or altered through this attack vector.\n\nIf the SSH daemon runs as root, this enables direct privilege escalation: an attacker can set the setuid bit on any binary, change ownership of sensitive files, or make system configuration world-writable.\n\nThis vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl and program routines ssh_sftpd:do_open/4 and ssh_sftpd:handle_op/4.\n\nThis issue affects OTP from OTP 17.0 before OTP 28.4.3, OTP 27.3.4.11 and OTP 26.2.5.20, corresponding to ssh from 3.0.1 before 5.5.3, 5.2.11.7 and 5.1.4.15."}],"affected":[{"vendor":"Erlang","product":"OTP","packageName":"ssh","packageURL":"pkg:otp/ssh?repository_url=https:%2F%2Fgithub.com%2Ferlang%2Fotp&vcs_url=git%20https:%2F%2Fgithub.com%2Ferlang%2Fotp.git","defaultStatus":"unknown","versions":[{"version":"3.01","status":"affected","lessThan":"*","changes":[{"at":"5.5.3","status":"unaffected"},{"at":"5.2.11.7","status":"unaffected"},{"at":"5.1.4.15","status":"unaffected"}],"versionType":"otp"}],"cpes":["cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"],"modules":["ssh_sftpd"],"programFiles":["src/ssh_sftpd.erl"],"programRoutines":[{"name":"ssh_sftpd:do_open/4"},{"name":"ssh_sftpd:handle_op/4"}],"repo":"https://github.com/erlang/otp"},{"vendor":"Erlang","product":"OTP","packageName":"erlang/otp","packageURL":"pkg:github/erlang/otp","defaultStatus":"unknown","versions":[{"version":"17.0","status":"affected","lessThan":"*","changes":[{"at":"28.4.3","status":"unaffected"},{"at":"27.3.4.11","status":"unaffected"},{"at":"26.2.5.20","status":"unaffected"}],"versionType":"otp"},{"version":"07b8f441ca711f9812fad9e9115bab3c3aa92f79","status":"affected","lessThan":"*","changes":[{"at":"28c5d5a6c5f873dc701b597276271763e7d1c004","status":"unaffected"}],"versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"],"modules":["ssh_sftpd"],"programFiles":["lib/ssh/src/ssh_sftpd.erl"],"programRoutines":[{"name":"ssh_sftpd:do_open/4"},{"name":"ssh_sftpd:handle_op/4"}],"repo":"https://github.com/erlang/otp"}],"references":[{"url":"https://github.com/erlang/otp/security/advisories/GHSA-28jg-mw9x-hpm5","tags":["vendor-advisory","related"]},{"url":"https://cna.erlef.org/cves/CVE-2026-32147.html","tags":["related"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-32147","tags":["related"]},{"url":"https://www.erlang.org/doc/system/versions.html#order-of-versions","tags":["x_version-scheme"]},{"url":"https://github.com/erlang/otp/commit/28c5d5a6c5f873dc701b597276271763e7d1c004","tags":["patch"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":5.3,"baseSeverity":"MEDIUM","exploitMaturity":"NOT_DEFINED","privilegesRequired":"LOW","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"LOW","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-22","description":"CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"EEF","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateUpdated":"2026-07-24T14:14:17.633Z"},"configurations":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"The SFTP subsystem must be configured with the <tt>root</tt> option in <tt>ssh_sftpd:subsystem_spec/1</tt>. The <tt>root</tt> option is not set by default."}],"value":"The SFTP subsystem must be configured with the root option in ssh_sftpd:subsystem_spec/1. The root option is not set by default."}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*","versionEndExcluding":"26.2.5.20","vulnerable":true},{"criteria":"cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*","versionEndExcluding":"27.3.4.11","versionStartIncluding":"27.0","vulnerable":true},{"criteria":"cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*","versionEndExcluding":"28.4.3","versionStartIncluding":"28.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"finder","value":"John Downey"},{"lang":"en","type":"remediation developer","value":"Michał Wąsowski"},{"lang":"en","type":"remediation reviewer","value":"Jakub Witczak"}],"source":{"discovery":"EXTERNAL"},"workarounds":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<ul><li>Do not use the <tt>root</tt> option in <tt>ssh_sftpd:subsystem_spec/1</tt>, and instead rely on OS-level chroot or container isolation to confine SFTP users.</li><li>Ensure the Erlang VM is not running as a privileged OS user. Running the VM as an unprivileged user limits the impact of this vulnerability, since attribute modifications are constrained by that user's OS-level permissions.</li></ul>"}],"value":"* Do not use the root option in ssh_sftpd:subsystem_spec/1, and instead rely on OS-level chroot or container isolation to confine SFTP users.\n* Ensure the Erlang VM is not running as a privileged OS user. Running the VM as an unprivileged user limits the impact of this vulnerability, since attribute modifications are constrained by that user's OS-level permissions."}],"x_generator":{"engine":"Vulnogram 0.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-21T13:11:06.946869Z","id":"CVE-2026-32147","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-21T13:11:40.325Z"}}]}}}