In its bid to protect the city from one computer security risk, the San Francisco District Attorney's Office may very well have created another.

The office of San Francisco District Attorney Kamala Harris has made public close to 150 usernames and passwords used by various departments to connect to the city's virtual private network. The passwords were filed this week as Exhibit A in a court document arguing against a reduction in US$5 million bail in the case of Terry Childs, who is accused of holding the city's network hostage by refusing to give up administrative networking passwords. Childs was arrested July 12 on charges of computer tampering and is being held in the county jail.

(See Why San Francisco's network admin went rogue)

Though they placed the passwords in the public record, city prosecutors do seem to think that they are sensitive.

The passwords, discovered on Childs' computer, pose an "imminent threat" to the city's computer network, according to the court filing. Childs could use the names and passwords to "impersonate any of the legitimate users in the City by using their password to gain access to the system," the motion against the bail reduction states.

Although the DA's office did not say what the passwords were used for, a source familiar with the situation said that they are for logging into the city's virtual private network, and that this type of information is something that a network administrator like Childs would be expected to have.

Posting these passwords in public creates a security risk, although the passwords are not enough to give a criminal access to the city's VPN. The passwords are so-called "phase one" passwords, and must be combined with a second password to access the network, the source said.

The passwords are used by city workers accessing the network from home computers or via laptops while they are outside of city offices. The passwords are for many city departments including the police department, the mayor's office, and the Department of Telecommunications and Information Services (DTIS), where Childs worked.

The city should be "moving very aggressively" to change the passwords as quickly as it can, said Robert Grapes, chief technologist of data center solutions for Cloakware, a vendor of password management software.

The DA's office initially declined to comment on the matter, but on Friday afternoon, spokeswoman Erica Derryck said via e-mail that "the court files have been amended accordingly." City technology workers have addressed the issue, she said. She did not say if that means the entire list of passwords had been removed from the public record.

The mayor's office, which supervises DTIS, did not return messages seeking comment for this story

To change the passwords, the city will have to reconfigure the VPN software running on every PC that connects remotely, which it has not yet done, the source said.

Some of the passwords would benefit from a change because they are identical to the VPN log-in name or extremely easy to guess.

Childs' case has been a top news story in San Francisco for nearly two weeks now.

For nine days after his July 12 arrest, he refused to hand over administrative passwords to the five central networking devices on the city's FiberWAN network, which carries about 60 percent of the city government's networking traffic. Childs, an engineer principal with DTIS who used the log-in Maggot617, had been engaged in a monthslong dispute with management, and held onto the passwords even after he was jailed.

On Monday, he gave them over to the mayor after a secret jailhouse meeting between the two. Childs' lawyer argues that because of departmental incompetence, the mayor was the only person qualified to be handed the keys to the network.

Given the criminal charges against Childs, the city should already be resetting these passwords, said Bruce Schneier, chief security technology officer at BT. "Fix it now," he said. "Go in there, expire everybody's passwords, and make them all log in again. Do it right now. This isn't hard."