{"id":464845,"date":"2022-10-17T13:00:58","date_gmt":"2022-10-17T11:00:58","guid":{"rendered":"https:\/\/mybroadband.co.za\/news\/?p=464845"},"modified":"2022-10-17T13:06:24","modified_gmt":"2022-10-17T11:06:24","slug":"microsoft-365-uses-weak-encryption-that-exposes-emails-to-snooping","status":"publish","type":"post","link":"https:\/\/mybroadband.co.za\/news\/security\/464845-microsoft-365-uses-weak-encryption-that-exposes-emails-to-snooping.html","title":{"rendered":"Microsoft 365 uses weak encryption that exposes emails to snooping"},"content":{"rendered":"

Security researchers from WithSecure have discovered an unpatchable vulnerability<\/strong><\/a> in Microsoft Office 365 Message Encryption (OME) that lets hackers infer the contents of encrypted messages.<\/p>\n

OME encrypts sent or received emails through the Electronic Code Book (ECB) mode, considered a broken or risky cryptographic algorithm.<\/p>\n

“This mode is generally insecure and can leak information about the structure of the messages sent, which can lead to partial or full message disclosure,” said WithSecure.<\/p>\n

BleepingComputer reported<\/strong><\/a> the issue with ECB is that repetitive areas in the plaintext data would have the same encrypted result when the same key is used.<\/p>\n

That results in a pattern that makes it easy for malicious actors to perform cryptanalysis on encrypted emails.<\/p>\n

“An attacker with a large database of messages may infer their content (or parts of it) by analysing relative locations of repeated sections of the intercepted messages,” WithSecure said.<\/p>\n

Attackers would require access to previously-leaked emails to exploit the vulnerability.<\/p>\n

“More emails make this process easier and more accurate, so it’s something attackers can perform after getting their hands on email archives stolen during a data breach, or by breaking into someone’s email account, email server or gaining access to backups,” said the researcher who discovered the flaw, Harry Sintonen.<\/p>\n

Microsoft has not patched the problem in 9 months<\/h2>\n

Sintonen reported the vulnerability to Microsoft on 11 January 2022 and received a $5,000 bounty for his efforts.<\/p>\n

However, after repeatedly following up with Microsoft about resolving the issue, the company finally said it did not consider the vulnerability met the bar for security servicing, nor was it considered a breach.<\/p>\n

“No code change was made, and so no CVE [common vulnerabilities and exposure] was issued for this report,” Microsoft said.<\/p>\n

“The root cause for the vulnerability appears to be a prior decision to use Electronic Codebook (ECB) mode of operation with message encryption and then maintaining compatibility with this poor decision,” Sintonen said.<\/p>\n

Sintonen said that end users or administrators of the email system had no option to enforce a more secure mode of operation.<\/p>\n

“Since Microsoft has no plans to fix this vulnerability, the only mitigation is to avoid using Microsoft Office 365 Message Encryption,” Sintonen advised.<\/p>\n

The weakness in ECB first came to light following the 2013 Adobe data breach.<\/p>\n

In that instance, researchers determined millions of passwords were leaked due to the use of ECB.<\/p>\n

Its weakness was highlighted again in 2020 after researchers found that popular video communications app Zoom used the same 128-bit key for encrypting video and audio using the algorithm with ECB mode.<\/p>\n

\n

Now read: Goodbye passwords \u2014 Google rolling out passkey support to Android and Chrome<\/a><\/h2>\n","protected":false},"excerpt":{"rendered":"

OME encrypts sent or received emails through the Electronic Code Book mode, regarded to be a broken or risky cryptographic algorithm.\u00a0<\/p>\n","protected":false},"author":23,"featured_media":456365,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_sma_x_autopost_status":"idle","_sma_x_autopost_error":"","_sma_x_post_id":"","_sma_facebook_post_id":"","_sma_instagram_post_id":"","_sma_x_attempts":0,"footnotes":""},"categories":[27],"tags":[71764,82015,6298,123,44440,82013],"class_list":["post-464845","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-security","tag-common-vulnerabilities-and-exposures-cve","tag-electronic-code-book-ecb","tag-encryption","tag-microsoft","tag-microsoft-365","tag-withsecure"],"_links":{"self":[{"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/posts\/464845"}],"collection":[{"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/users\/23"}],"replies":[{"embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/comments?post=464845"}],"version-history":[{"count":1,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/posts\/464845\/revisions"}],"predecessor-version":[{"id":464879,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/posts\/464845\/revisions\/464879"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/media\/456365"}],"wp:attachment":[{"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/media?parent=464845"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/categories?post=464845"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/tags?post=464845"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}