A vulnerability in a smart access control system used in thousands of rental homes in the US allows anyone to remotely control any lock in an affected home. But Chirp Systems, the company that makes the system, has ignored requests to fix the flaw.
The US cyber security agency CISA went public with a safety advisory last week saying that phone apps developed by Chirp, which residents use in place of a key to access their homes, “improperly store” encrypted credentials that can be used to remotely control any Chirp-compatible smart lock.
Apps that rely on passwords stored in their source code, known as hard-coded credentials, are a security risk because anyone can extract and use those credentials to perform actions that impersonate the app. In this case, the credentials allowed anyone to remotely lock or unlock a Chirp-connected door lock over the Internet.
In its advisory, CISA said that successful exploitation of the flaw “could allow an attacker to take control and gain unrestricted physical access” to smart locks connected to a Chirp smart home system. The cybersecurity agency gave the vulnerability a severity score of 9.1 out of a maximum of 10 for its “low attack sophistication” and its ability to be remotely exploited.
The cybersecurity agency said Chirp Systems has not responded to CISA or the researcher who found the vulnerability.
Security researcher Matt Brown said veteran security reporter Brian Krebs that it notified Chirp of the security issue in March 2021, but that the vulnerability remains unresolved.
Chirp Systems is one of a growing number of companies in the real estate technology space providing keyless access controls integrated with smart home technologies to rental giants. Rental companies are increasingly forcing renters to allow the installation of smart home equipment as dictated by their leases, but it’s murky at best who takes responsibility or ownership when security issues arise.
Property and rental giant Camden Property Trust signs deal in 2020 to launch Chirp-connected smart locks more than 50,000 units in over a hundred properties. It’s unclear whether affected properties like Camden are aware of the vulnerability or have taken action. Kim Callahan, a spokesman for Camden, did not respond to a request for comment.
Chirp was acquired by real estate management software giant RealPage in 2020 and RealPage was acquired by private equity giant Thoma Bravo later that year in a $10.2 billion deal. RealPage treats many legal challenges after claims the rent adjustment software uses secret and proprietary algorithms to help landlords raise the highest possible rents for tenants.
Neither RealPage nor Thoma Bravo have yet acknowledged the vulnerabilities in the software it acquired, or said whether they plan to notify affected residents of the security risk.
Jennifer Bowcock, a spokeswoman for RealPage, did not respond to TechCrunch’s requests for comment. Megan Frank, a spokeswoman for Thoma Bravo, also did not respond to requests for comment.
