CVE-2026-48858
Description
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.
Statement
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.
Mitigation
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | 6.5 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | Low | Low | N/A |
| Integrity Impact | Low | Low | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Integrity
Technical Impact: Execute Unauthorized Code or Commands
Access Control
Technical Impact: Bypass Protection Mechanism
By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
Frequently Asked Questions
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