Port 5Remote Job Entry
Remote Job Entry (RJE) is an early protocol designed for submitting batch processing jobs from remote locations to mainframe computers. It facilitated offsite users or departments in efficiently sending jobs and retrieving results without direct access to the data center. RJE was primarily used in large enterprise and academic environments before the advent of modern distributed and interactive systems..
- transport
- tcp · udp
- in transit
- cleartext
- assignment
- official
- risk
- 4/10
- lookups
- 9,732
2 transports registered
payload readable on path
registered with iana
caution
rank 490 of 993 · top 49%
Technical Details
what runs on :5Remote Job Entry (RJE) is a protocol and system that enables users to submit batch jobs remotely to a mainframe or central computer for processing. Originating in the early days of terminal computing, RJE supported operations where computing resources were centralized, and remote offices or departments sent job control language (JCL) scripts over network connections to be queued and executed in bulk.
The protocol typically employed telnet-based or proprietary communication methods that allowed job files, control information, and data input to be transferred securely (though not encrypted by today’s standards) between remote terminals and the mainframe. Once the mainframe processed the batch jobs, output files, logs, and printed reports could be retrieved in a similar manner.
As a batch-oriented system, RJE optimized resource utilization by grouping jobs, reducing idle time on expensive mainframes, and enabling distributed users to leverage centralized computing without requiring real-time interaction. With advances in networking and interactive systems, RJE has largely been supplanted by more modern protocols and distributed processing techniques.
Security Information
exposure of :5risk score
4/ 10caution
worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.
network services averages 3.9 across 604 ports — this one sits 0.1 above.
in transit
cleartext
credentials and payloads are readable by anyone on path
assignment
official
registered with iana for this service — scanners fingerprint it by number
reachable over
tcp · udp
udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite
security overview
Common vulnerabilities associated with RJE include:
- Lack of encryption leading to potential eavesdropping and interception
- Weak or absent authentication mechanisms, enabling unauthorized job submissions
- Susceptibility to job injection or malicious batch file submission
- Exposure to man-in-the-middle attacks due to plaintext communication
Mitigations for RJE-related risks involve:
- Segmenting legacy RJE systems behind firewalls and VPNs
- Using network access controls to limit submission sources
- Monitoring job submission traffic for anomalies
- Where possible, replacing or wrapping RJE services with secure tunneling solutions (e.g., SSH)
- Moving toward modern, authenticated, and encrypted protocols or job submission interfaces
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risk mix of the 8 listed
- caution100%
0 of 8 encrypted