Port 11211Memcached
Memcached is a high‑performance, distributed memory caching system designed to optimize dynamic web applications by alleviating database load. It temporarily stores key-value pairs in RAM to accelerate data retrieval and reduce latency for frequently accessed data..
- transport
- unknown
- in transit
- cleartext
- assignment
- unofficial
- risk
- 4/10
- lookups
- 7,167
single transport
payload readable on path
used by convention
caution
rank 715 of 993 · top 72%
Technical Details
what runs on :11211Technical Overview
Memcached is an open-source, high-speed, in-memory key-value store primarily utilized as a caching solution. Designed to be simple yet powerful, it helps reduce the number of times a database or API must be queried by caching the results of calls. Clients of Memcached connect to its server through a network socket, typically communicating via a simple text-based protocol.
Architecture & Communication
Memcached operates in a client-server architecture where multiple application nodes interact with a pool of Memcached servers. These servers are distributed without clustering logic; the client implements hashing to distribute keys. The default communication ports are 11211, over both TCP and UDP, though in many deployments only TCP is used owing to reliability concerns.
Deployment Considerations
Memcached is widely deployed alongside web frameworks (like Django, Rails, or PHP) to improve scalability. It does not provide persistence or replication by design, focusing solely on performance. The simplicity of the protocol and statelessness make Memcached extremely fast but reliant on proper application logic for handling cache invalidation and fallback.
Security Information
exposure of :11211risk score
4/ 10caution
worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.
web services averages 3.9 across 112 ports — this one sits 0.1 above.
in transit
cleartext
credentials and payloads are readable by anyone on path
assignment
unofficial
used by convention, not registered — what answers here varies by deployment
reachable over
unknown
every listening transport is another surface to filter at the edge
security overview
Common Vulnerabilities
- Unauthenticated access: Memcached historically does not implement authentication by default, leaving it exposed to unauthorized users if improperly firewalled.
- Open relay abuse: UDP support can be exploited for high-bandwidth reflection DDoS attacks, amplifying small packets into large payloads against a target.
- Information leakage: Unrestricted access may allow attackers to dump sensitive cached data.
Mitigations
- Network segmentation: Deploy Memcached behind internal firewalls or private network segments to restrict access.
- Disable UDP: Turn off UDP support to prevent reflection/amplification attacks.
- Authentication: Use SASL authentication or enable encryption proxies (like stunnel) where supported.
- Monitoring & patching: Keep software updated to mitigate known exploits and monitor for unusual request patterns indicative of abuse.
- Access controls: Limit access to trusted hosts through IP whitelisting or security groups.
Related Ports
the 8 most looked-up other ports in web services — 112 ports carry that label.
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|---|---|---|---|---|---|
| :8888 | Sun Answerbook & Alt HTTP | TCP | Web Services | caution | 123.9k |
| :8000 | Intel Remote Desktop / Alternate HTTP Port | TCP | Web Services | safe | 84.3k |
| :8888 | NewsEDGE | TCPUDP | Web Services | caution | 83.3k |
| :8888 | HTTP Alternative Port | TCP | Web Services | caution | 76.5k |
| :8888 | GNUmp3d Streaming HTTP | TCP | Web Services | caution | 76.3k |
| :9080 | Groove RPC | TCPUDP | Web Services | caution | 70.8k |
| :8881 | Atlasz Secure Server | TCP | Web Services | caution | 67.6k |
| :80 | HTTP | TCPUDP | Web Services | caution | 67.3k |
risk mix of the 8 listed
- safe13%
- caution88%
0 of 8 encrypted