A previously unknown security flaw in Bugzilla — a popular online bug-tracking tool used by Mozilla and many of the open source Linux distributions — allows anyone to view detailed reports about unfixed vulnerabilities in a broad swath of software. Bugzilla is expected today to issue a fix for this very serious weakness, which potentially exposes a veritable gold mine of vulnerabilities that would be highly prized by cyber criminals and nation-state actors.

Multiple software projects use Bugzilla to keep track of bugs and flaws that are reported by users. The Bugzilla platform allows anyone to create an account that can be used to report glitches or security issues in those projects. But as it turns out, that same reporting mechanism can be abused to reveal sensitive information about as-yet unfixed security holes in software packages that rely on Bugzilla.

A developer or security researcher who wants to report a flaw in Mozilla Firefox, for example, can sign up for an account at Mozilla’s Bugzilla platform. Bugzilla responds automatically by sending a validation email to the address specified in the signup request. But recently, researchers at security firm Check Point Software Technologies discovered that it was possible to create Bugzilla user accounts that bypass that validation process.

“Our exploit allows us to bypass that and register using any email we want, even if we don’t have access to it, because there is no validation that you actually control that domain,” said Shahar Tal, vulnerability research team leader for Check Point. “Because of the way permissions work on Bugzilla, we can get administrative privileges by simply registering using an address from one of the domains of the Bugzilla installation owner. For example, we registered as admin@mozilla.org, and suddenly we could see every private bug under Firefox and everything else under Mozilla.”

Bugzilla is expected today to release updates to remove the vulnerability and help further secure its core product. Update, 1:59 p.m. ET: An update that addresses this vulnerability and several others in Bugzilla is available here.

“An independent researcher has reported a vulnerability in Bugzilla which allows the manipulation of some database fields at the user creation procedure on Bugzilla, including the ‘login_name’ field,” said Sid Stamm, principal security and privacy engineer at Mozilla, which developed the tool and has licensed it for use under the Mozilla public license.

“This flaw allows an attacker to bypass email verification when they create an account, which may allow that account holder to assume some privileges, depending on how a particular Bugzilla instance is managed,” Stamm said. “There have been no reports from users that sensitive data has been compromised and we have no other reason to believe the vulnerability has been exploited. We expect the fixes to be released on Monday.”

The flaw is the latest in a string of critical and long-lived vulnerabilities to surface in the past year — including Heartbleed and Shellshock — that would be ripe for exploitation by nation state adversaries searching for secret ways to access huge volumes of sensitive data.

“The fact is that this was there for 10 years and no one saw it until now,” said Tal. “If nation state adversaries [had] access to private bug data, they would have a ball with this. There is no way to find out if anyone did exploit this other than going through user list and seeing if you have a suspicious user there.”

Like Heartbleed, this flaw was present in open source software to which countless developers and security experts had direct access for years on end.

“The perception that many eyes have looked at open source code and it’s secure because so many people have looked at it, I think this is false,” Tal said. “Because no one really audits code unless they’re committed to it or they’re paid to do it. This is why we can see such foolish bugs in very popular code.”

Update, Oct. 7, 12:44 p.m. ET: Mozilla issued the following statement in response to this story:

Regarding the comment in the first paragraph: While it’s a theoretical possibility that other Bugzilla installations expose security bugs to “all employees,” Mozilla does not do this and as a result our security bugs were not available to potential exploiters of this flaw.

mozilla -employee” access. We do actively use that classification, but not for security bugs. At no time did Check Point get “administrative privileges” on bugzilla. mozilla .org . They did create an account called admin@ mozilla .org that would inherit “netscapeconfidential” privileges, but we stopped using this privilege level long before the reported vulnerability was introduced. They also created “ admin@ mozilla .com ” which inherited “-employee” access. We do actively use that classification, but not for security bugs.

Tags: Bugzilla, Check Point Software Technologies, Heartbleed, Mozilla, Shahar Tal, Shellshock