Finger Protocol Vulnerabilities Exploited for Social Engineering Attacks
Severity: Medium (Score: 48.9)
Sources: handwiki.org, gunkies.org
Published: · Updated:
Keywords: finger, protocol, information, network, users, name, user
Severity indicators: ot
Summary
The Finger protocol, originally designed for user information exchange, has been exploited for social engineering attacks. Hackers utilize the protocol to gather sensitive user data, such as email addresses and phone numbers, from organizations. This information can be used to impersonate employees and initiate phishing attacks. The protocol's ease of access and the detailed user information it provides raise significant privacy and security concerns. While the Finger protocol was useful in the early days of networking, its vulnerabilities are now being actively targeted by malicious actors. Organizations relying on this protocol are at risk of data breaches and social engineering attacks. The current status indicates ongoing exploitation attempts, necessitating immediate attention from cybersecurity professionals. Key Points: • The Finger protocol is being exploited for social engineering attacks. • Hackers can obtain sensitive user information, facilitating impersonation. • Organizations using the Finger protocol are at increased risk of data breaches.
Detailed Analysis
**Impact** Organizations with legacy systems running the Finger protocol are affected, including those using Unix, Unix-like systems, and some Windows environments. The protocol exposes user information such as login status, email addresses, and full names, which can be leveraged for social engineering attacks. This exposure risks unauthorized access to sensitive corporate data and facilitates targeted phishing campaigns. No specific sectors, geographies, or quantitative impact data are provided. **Technical Details** The attack vector involves exploiting the Finger protocol running on TCP port 79 to gather user information remotely. Adversaries use finger clients to query user details, including contents of .plan and .project files, to craft social engineering attacks. Historical vulnerabilities include buffer overflow exploits like those used by the 1988 Morris worm, but no current CVEs or malware are specified. The articles do not provide specific indicators of compromise or infrastructure details. **Recommended Response** Disable the Finger service on all systems where it is not explicitly required, especially on Internet-facing hosts. Monitor network traffic for unexpected connections to TCP port 79 and block or restrict access where possible. Educate employees to recognize social engineering attempts that may leverage information obtained via the Finger protocol. No specific patches or detections are mentioned in the sources.
Source articles (2)
- He named his new program after that gesture — handwiki.org · 2026-05-27
In computer networking , the Name/Finger protocol and the Finger user information protocol are simple network protocols for the exchange of human-oriented status and user information. The Name/Finger… - Finger — gunkies.org · 2026-05-27
Finger is a network protocol used to provide information users logged in on a host . It was first invented by Les Earnest as a tool to see the physical location of users and free terminals at the Stan…
Timeline
- Date unkno — Finger protocol developed: Les Earnest created the Finger protocol to provide user information at the Stanford AI Lab.
- Date unkno — Finger protocol extended to ARPANET: The protocol was expanded to allow information exchange between ARPANET hosts, enhancing its utility.
- Date unkno — Vulnerabilities exploited for social engineering: Hackers began using the Finger protocol to gather user data for social engineering attacks.
Related entities
- Malware (Attack Type)
- Worm (Attack Type)
- CWE-120 - Classic Buffer Overflow (Cwe)
- host.it (Domain)
- lab.in (Domain)
- Morris Worm (Malware)
- Unix (Platform)
- Windows (Platform)