E-commerce giant eBay has told all its users to change their passwords in the wake of a cyber attack on the popular online marketplace.

In a statement on the company's website, the US-based business said they were asking users to reset their passwords after an attack "compromised a database containing encrypted passwords and other non-financial data".

The site, which has more than 14 million active users in the UK, was quick to say that it believes no unauthorised access was gained to personal data, but that a password reset was the best practice to help ensure security.

"Cyberattackers compromised a small number of employee log-in credentials, allowing unauthorised access to eBay's corporate network," said the statement.

"Working with law enforcement and leading security experts, the company is aggressively investigating the matter and applying the best forensics tools and practices to protect customers. Information security and customer data protection are of paramount importance to eBay Inc, and eBay regrets any inconvenience or concern that this password reset may cause our customers.

"We know our customers trust us with their information, and we take seriously our commitment to maintaining a safe, secure and trusted global marketplace."

eBay said that the database was breached at some point in late February and early March, with access gained to personal customer information including password, address and date of birth. However, the company says that no financial information has been compromised as this data is stored on a separate database under a different encryption.

"The compromised employee log-in credentials were first detected about two weeks ago. Extensive forensics subsequently identified the compromised eBay database, resulting in the company's announcement today," said the statement.

"The company said it has seen no indication of increased fraudulent account activity on eBay. The company also said it has no evidence of unauthorised access or compromises to personal or financial information for PayPal users. PayPal data is stored separately on a secure network, and all PayPal financial information is encrypted."

The internet is still recovering from the Heartbleed bug, a flaw in the OpenSSL encryption on computers that protects user information when someone is online.

The flaw had been present for two years undetected, and offered hackers a way into personal accounts across the web. UK parental advice site Mumsnet was the first to admit they had been a victim of the bug. Fixes, or "patches", have since been applied across the web as sites recover from the bug.

A spokesman for eBay said: "Our customers are our highest priority; and to ensure they continue to have a safe, secure and trusted experience on eBay, we will be asking all eBay users to change their passwords. Recently, our company discovered a cyberattack on our corporate information network which compromised a database containing eBay user passwords.

"There is no evidence that any financial information was accessed or compromised; however we are taking every precaution to protect our customers."

Michela Menting, cybersecurity practice director at technology market experts ABI Research, said that eBay's security set-up and response should make users feel reassured.

"It's early days yet but eBay appears to be going about it the right way. It seems that the attackers managed to gain employee credentials through social engineering - a difficult type of fraud that is tricky to avoid completely, even with the best defences in place. Consequently incident response mechanisms have to be iron clad in order to minimise fall-out. It also appears that eBay have effectively siloed databases for financial info from customer information. The fact that passwords were encrypted is also reassuring.

"Finally I think their timely public announcement - two weeks after discovery - helps to reassure not only public opinion, but also their own brand reputation. Transparency when dealing with incident response for an event that has affected customers, in this case millions, is highly commendable and helps to keep a higher level of trust than if the news were revealed by another source - it means that eBay takes security seriously."

However Ms Menting believes that the online marketplace is not completely clear of scrutiny just yet, with the publicity of this attack likely to draw closer inspection of eBay's existing security procedures.

"It remains to be seen whether the current defence and response mechanisms in place will stand up to scrutiny now that the attack has been publicised," she said.

"Having a plan in place does not always mean all procedures were viable or solid. If they crumble under the dissection by security professionals, we may yet see another CEO resign. So far however, it seems eBay has matters well in hand."