Tesco in unencrypted password email reminder rumble
Price check on salt
Magic Quadrant for Enterprise Backup/Recovery
Tesco's admission that it still merrily emails passwords to punters in plain text has alarmed anyone with a grasp of computer security.
The UK's supermarket behemoth reassured the world on Sunday that it stores passwords for online shopping accounts in an encrypted format, and only decrypts them when users forget their login credentials and request a reminder via email.
This cut little ice with many Reg readers, who contacted us in large numbers on Monday morning. They pointed out that the method is undesirable because it fails to meet the security industry's best practices. It would be far better if Tesco switched to a secure password reset process with salted hashes for users' login credentials.
One (unlikely) danger is that these unencrypted email password reminders could be intercepted and used by crooks. But the bigger issue is that the method implies that the grocer stores passwords in a way that could allow anyone who infiltrates the website to uncover the original plaintext credentials: if Tesco can decrypt stored passwords for reminder emails, hackers can too.
The password reminder issue was raised again at the weekend by developer Troy Hunt but the same issue was actually first reported five years ago, back in 2007.
It's poor practice to send out password reminders in the clear-text but Tesco is hardly alone in this, and it's hardly the most wretched of security sins. The tone and severity of criticism against Tesco would be justified had its systems had actually been hacked and the passwords exposed - as has happened to other and still more prominent organisations in recent times - but this doesn't appear to be the case.
The password reminder issue is just the most obvious in a security of security mistakes by the grocer, according to Hunt, who list the various flubs in a blog post here. Other problems include using unencrypted authentication cookies and mixing up encrypted and unencrypted content on a secure page, behaviour that likely to generate browser warnings that most users will find confusing. For good measure Tesco's website is insecurely configured and running IIS 6, a seven-year-old and twice superseded version of Microsoft's web server software.
We asked Tesco for a more substantive response covering these various concerns but at the time of posting we're yet to hear back from the retailer. We'll update this story as and when we hear more. ®
COMMENTS
One (unlikely) danger is that these unencrypted email password reminders could be intercepted and used by crooks. But the bigger issue is that the method implies that the grocer stores password hashes in an unsalted format. If there was any kind of breach that exposed these password hashes then the corresponding plain text passwords can be extracted from the stored hashes using a brute force attack and rainbow lookup tables.
Not to be too pedantic, but these aren't hashes. Hashes are one way (salted or otherwise), these would actually be encrypted passwords. How is it the Reg calls hashes encrypted passwords, but when they could use the right term (even if by accident) they still cock it up.
Pales in comparison to the cock-up by Tesco though. When it comes to security every little helps
Getting me coat
Re: Dear [password]
Ah - sounds like she has accidentally entered her name in the "Name" field and password in the "Password" field.
If she enters her password in the "Name" field and name in the "Password" field, this issue will be resolved.
We randomise the fields to increase your security. Or hide our mistakes. Remember: every little helps....
Tesco Web Security Support (deceased)
Re: So....
You missed the point, you shouldn't be able to recover your old password. If you forget your password, it should make you reset it to a new one.
IT infrastructure monitoring strategies
Agentless Backup is Not a Myth
Top 10 SIEM implementer’s checklist
Steps to Take Before Choosing a Business Continuity Partner
Enabling efficient data center monitoring
