The talk is the most detailed presentation, to date, of a range of flaws in Deere software and services that were first identified and disclosed to the company in April. The disclosure of two of those flaws in the company’s public-facing web applications set off a scramble by Deere and other agricultural equipment makers to patch the flaws, unveil a bug bounty program and to hire cyber security and embedded device security talent.
In addition to a slew of common web flaws like Cross Site Scripting- and account enumeration bugs linked to Deere’s web site and public APIs, the researchers discovered a vulnerability (CVE-2021-27653) in third-party software by Pega Systems, a maker of customer relationship management (CRM) software that Deere uses. A misconfiguration of that software gave the researchers administrative access to the remote, back end Pegasystems server. With wide ranging, administrative access to the production backend Pega server, the researchers were able to obtain other administrative Pegasystems credentials including passwords, security audit logs, as well as John Deere’s OKTA signing certificate for the Pegasystems server, according to the presentation. In an email statement to The Security Ledger, a John Deere spokesperson said that “none of the claims — including those identified at DEF CON — have enabled access to customer accounts, agronomic data, dealer accounts, or sensitive personal information,” though data included in the presentation as well as prior public disclosures make clear that sensitive data on Deere employees, equipment, customers and suppliers was exposed.