Server-Side Request Forgery (SSRF) vulnerability in Erlang/OTP ftp (ftp_internal module) allows FTP bounce attacks and SSRF via an unvalidated PASV response IP address. The ftp_internal:handle_ctrl_result/2 PASV handler (mode=passive, ipfamily=inet, ftp_extension=false) extracts the IP address from the server's 227 response and passes it directly to gen_tcp:connect/4 without validating it against the control connection peer address. The adjacent EPSV handlers correctly call peername(CSock) to derive the IP from the control connection, but the PASV handler does not. A malicious or compromised FTP server can redirect the client's data connection to an arbitrary internal host and port. On read operations (ftp:ls/1,2, ftp:nlist/1,2, ftp:recv/2,3), data from the redirected target is returned to the caller. On write operations (ftp:send/2,3, ftp:append/2,3), file content is sent to the redirected target. This enables SSRF against internal hosts, cloud metadata endpoints, and FTP bounce attacks against third-party hosts. The vulnerable path is the default configuration (mode=passive, ipfamily=inet, ftp_extension=false). RFC 2577 section 3 explicitly recommends validating the PASV response IP against the control connection peer. The ftp application is deprecated and scheduled for removal in OTP-30. This vulnerability is associated with program files lib/inets/src/ftp/ftp_internal.erl (inets 5.10.4 through 6.5, OTP 17.4 through 20.3) and lib/ftp/src/ftp_internal.erl (ftp 1.0 and later, OTP 21.0 and later). This issue affects OTP from OTP 17.4 before 29.0.2, 28.5.0.2 and 27.3.4.13 corresponding to inets from 5.10.4 before 7.0 and ftp from 1.0 before 1.2.6, 1.2.4.1 and 1.2.3.1.

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the d87e0681-64d4-11f1-ab11-4c526214c986 advisory.

    https://github.com/erlang/otp/security/advisories/GHSA-24cv-hwgr-37fq reports:
    The FTP client in passive mode did not validate the IP               address returned in the server's response, allowing a               compromised or malicious server to redirect the data connection               to an arbitrary host. This enables server-side request forgery               (SSRF) and FTP bounce attacks.

Tenable has extracted the preceding description block directly from the FreeBSD security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Server-Side Request Forgery (SSRF) vulnerability in Erlang/OTP ftp (ftp_internal module) allows FTP bounce     attacks and SSRF via an unvalidated PASV response IP address. The ftp_internal:handle_ctrl_result/2 PASV     handler (mode=passive, ipfamily=inet, ftp_extension=false) extracts the IP address from the server's 227     response and passes it directly to gen_tcp:connect/4 without validating it against the control connection     peer address. The adjacent EPSV handlers correctly call peername(CSock) to derive the IP from the control     connection, but the PASV handler does not. A malicious or compromised FTP server can redirect the client's     data connection to an arbitrary internal host and port. On read operations (ftp:ls/1,2, ftp:nlist/1,2,     ftp:recv/2,3), data from the redirected target is returned to the caller. On write operations     (ftp:send/2,3, ftp:append/2,3), file content is sent to the redirected target. This enables SSRF against     internal hosts, cloud metadata endpoints, and FTP bounce attacks against third-party hosts. The vulnerable     path is the default configuration (mode=passive, ipfamily=inet, ftp_extension=false). RFC 2577 section 3     explicitly recommends validating the PASV response IP against the control connection peer. The ftp     application is deprecated and scheduled for removal in OTP-30. This vulnerability is associated with     program files lib/inets/src/ftp/ftp_internal.erl (inets 5.10.4 through 6.5, OTP 17.4 through 20.3) and     lib/ftp/src/ftp_internal.erl (ftp 1.0 and later, OTP 21.0 and later). This issue affects OTP from OTP 17.4     before 29.0.2, 28.5.0.2 and 27.3.4.13 corresponding to inets from 5.10.4 before 7.0 and ftp from 1.0     before 1.2.6, 1.2.4.1 and 1.2.3.1. (CVE-2026-48858)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
320573	FreeBSD : Erlang/OTP -- FTP passive-mode client does not validate server response IP (d87e0681-64d4-11f1-ab11-4c526214c986)	Nessus	FreeBSD Local Security Checks	medium
320497	Linux Distros Unpatched Vulnerability : CVE-2026-48858	Nessus	Misc.	medium

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CVE-2026-48858

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