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Disclaimer: as technology changes, advisories may become out of date or may no longer be relevant, please refer to the "Date" section of the header to be sure the advisory is recent as pertains to your situation.

Digibase Security Advisory - RCN Stores Passwords Plaintext

Keywords: plaintext password, disclosure

DBSA ID: 2018-092201

Regarding: RCN Stores Passwords Plaintext

Writeup: Kradorex Xeron (talk) 22:13, 22 September 2018 (EDT)

Date: 2018 09 22

Last Modified: 20180922223547 by Kradorex Xeron

Who should take note: RCN Customers


Priority: HIGH

Rationale: RCN Customers should maintain continuous monitoring of the situation.

Severity: HIGH

Rationale: Plaintext password storage is a violation of fundamental security standards and plaintext password storage is treated with the same regard as password compromise.


Rationale: All RCN Customers are subject.


RCN is an Internet Services Provider (ISP) in the United States.

RCN has been identified to store customer account passwords (for my.rcn.com/login and related systems) plaintext, without hashing in violation of security standards. Anyone with read access to the RCN customer login database may login to any RCN customer's account, including any attackers who breach their login database or disgruntled employees recording customer passwords. The company has gone as far as to say that plaintext password storage is a matter of company policy, making the issue that much worse.

Further explanation

The industry standard method of storing passwords is through running any provided password through a mathematical computation similar to encryption (but irreversible) called "hashing". When a user goes to login, the login password is also hashed and compared to the stored hashed password. Attempts to use the hash itself to login is run through the computation again, providing a different result and fails. If a user forgets a password, it is lost and must be changed.

This ensures that even if an attacker gets the password list, it doesn't automatically empower the attacker to login to any user account as they don't have the original passwords. This is a well researched and established method for password storage.


RCN customers are advised that they should treat the passwords supplied to the company as compromised at this time. Further, RCN customers may wish to contact the company and insist the company transition to a one-way "hashing" password storage system.