Описание
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 OTP 29.0.2, OTP 28.5.0.2 and OTP 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.
A flaw was found in Erlang/OTP's FTP (File Transfer Protocol) client, specifically within the ftp_internal module. A remote attacker, by operating a malicious or compromised FTP server, could exploit an unvalidated IP address in the server's passive mode (PASV) response. This vulnerability, known as Server-Side Request Forgery (SSRF), allows the attacker to redirect the client's data connection to an arbitrary internal host and port. This can lead to information disclosure from internal systems or the sending of sensitive data to unintended third-party hosts, enabling FTP bounce attacks.
Отчет
This Moderate severity flaw in the Erlang/OTP FTP client allows a remote attacker to perform Server-Side Request Forgery (SSRF) by redirecting data connections to arbitrary internal hosts. This occurs when the client connects to a malicious or compromised FTP server that provides an unvalidated IP address in its passive mode response, potentially leading to information disclosure or data exfiltration from internal systems.
Меры по смягчению последствий
To mitigate this vulnerability, restrict network access for systems using the Erlang/OTP FTP client to only trusted FTP servers. Implement firewall rules to limit outbound connections from Erlang/OTP applications to known, legitimate FTP server IP addresses and ports. If the Erlang/OTP ftp application is not required, consider disabling or removing it to eliminate the attack surface.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat OpenStack Platform 16.2 | erlang | Under investigation | ||
| Red Hat OpenStack Platform 17.1 | erlang | Under investigation | ||
| Red Hat OpenStack Platform 18.0 | erlang | Under investigation |
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Дополнительная информация
Статус:
EPSS
6.5 Medium
CVSS3
Связанные уязвимости
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 at...
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 atta
ftp client PASV response IP not validated against control peer, enabling SSRF and FTP bounce attacks
Server-Side Request Forgery (SSRF) vulnerability in Erlang/OTP ftp (ft ...
EPSS
6.5 Medium
CVSS3