CVE-2026-48858

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 ftpinternal:handlectrlresult/2 PASV handler (mode=passive, ipfamily=inet, ftpextension=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/ftpinternal.erl (inets 5.10.4 through 6.5, OTP 17.4 through 20.3) and lib/ftp/src/ftpinternal.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.

Database specific

{
    "unresolved_ranges": [
        {
            "source": "AFFECTED_FIELD",
            "extracted_events": [
                {
                    "introduced": "5.10.4"
                },
                {
                    "fixed": "7.0"
                },
                {
                    "introduced": "1.0"
                },
                {
                    "fixed": "*"
                },
                {
                    "introduced": "17.4"
                },
                {
                    "fixed": "*"
                },
                {
                    "introduced": "be95772ee1fcfe71045ef070130bea7a910b81e3"
                },
                {
                    "fixed": "*"
                }
            ]
        }
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48858.json",
    "cna_assigner": "EEF",
    "cwe_ids": [
        "CWE-918"
    ]
}

References

Affected packages

Git / github.com/erlang/otp

Affected ranges

Type

GIT

Repo

https://github.com/erlang/otp

Events

Introduced

af87b1c3d4897840d8247589a88d3611106ecedc

Fixed

f835a5a32aeeb70778c958b5c01a401973e8fbe2

Introduced

9e6f6742c4d9e9915ee8af0dcb7d97cf1f836116

Fixed

4567096bddd1ecddb7c973019ca7e769f486aa8f

Introduced

550d7b7898706c7822362c42e7b93120c1d1f29a

Fixed

36b336d7675edfb976768465c5067bc8bc16ee9a

Fixed

2691a806231ffd0490a8a9e20500dec0c7e73727

Fixed

521bcfa24407ee8cb5614823cf905c37ea3aa605

Database specific

{
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ],
    "cpe": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "17.4"
        },
        {
            "fixed": "27.3.4.13"
        },
        {
            "introduced": "28.0"
        },
        {
            "fixed": "28.5.0.2"
        },
        {
            "introduced": "29.0"
        },
        {
            "fixed": "29.0.2"
        }
    ]
}

Affected versions

OTP-28.*

OTP-28.0

OTP-28.1

OTP-28.4

OTP-28.5

OTP-28.5.0.1

OTP-29.*

OTP-29.0

OTP-29.0.1

Other

patch-base-28

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48858.json"