Security
Headlines
HeadlinesLatestCVEs

Headline

State-Sponsored Hackers Likely Exploited MS Exchange 0-Days Against ~10 Organizations

Microsoft on Friday disclosed that a single activity group in August 2022 achieved initial access and breached Exchange servers by chaining the two newly disclosed zero-day flaws in a limited set of attacks aimed at less than 10 organizations globally. "These attacks installed the Chopper web shell to facilitate hands-on-keyboard access, which the attackers used to perform Active Directory

The Hacker News
#vulnerability#web#microsoft#js#intel#rce#ssrf#auth#zero_day#The Hacker News

Microsoft on Friday disclosed that a single activity group in August 2022 achieved initial access and breached Exchange servers by chaining the two newly disclosed zero-day flaws in a limited set of attacks aimed at less than 10 organizations globally.

“These attacks installed the Chopper web shell to facilitate hands-on-keyboard access, which the attackers used to perform Active Directory reconnaissance and data exfiltration,” the Microsoft Threat Intelligence Center (MSTIC) said in a Friday report.

The weaponization of the vulnerabilities is expected to ramp up in the coming days, Microsoft further warned, as malicious actors co-opt the exploits into their toolkits, including deploying ransomware, due to the “highly privileged access Exchange systems confer onto an attacker.”

The tech giant attributed the ongoing attacks with medium confidence to a state-sponsored organization, adding it was already investigating these attacks when the Zero Day Initiative disclosed the flaws to Microsoft Security Response Center (MSRC) earlier this month on September 8-9, 2022.

The two vulnerabilities have been collectively dubbed ProxyNotShell, owing to the fact that “it is the same path and SSRF/RCE pair” as ProxyShell but with authentication, suggesting an incomplete patch.

The issues, which are strung together to achieve remote code execution, are listed below -

  • CVE-2022-41040 - Microsoft Exchange Server Server-Side Request Forgery Vulnerability
  • CVE-2022-41082 - Microsoft Exchange Server Remote Code Execution Vulnerability

“While these vulnerabilities require authentication, the authentication needed for exploitation can be that of a standard user,” Microsoft said. “Standard user credentials can be acquired via many different attacks, such as password spray or purchase via the cybercriminal economy.”

The vulnerabilities were first discovered by Vietnamese cybersecurity company GTSC as part of its incident response efforts for a customer in August 2022. A Chinese threat actor is suspected to be behind the intrusions.

The development comes as the U.S. Cybersecurity and Infrastructure Security Agency (CISA) added the two Microsoft Exchange Server zero-day vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, requiring federal agencies to apply the patches by October 21, 2022.

Microsoft said that it’s working on an “accelerated timeline” to release a fix for the shortcomings. It has also published a script for the following URL Rewrite mitigation steps that it said is “successful in breaking current attack chains” -

  • Open IIS Manager
  • Select Default Web Site
  • In the Feature View, click URL Rewrite
  • In the Actions pane on the right-hand side, click Add Rule(s)…
  • Select Request Blocking and click OK
  • Add the string “.*autodiscover\.json.*\@.*Powershell.*” (excluding quotes)
  • Select Regular Expression under Using
  • Select Abort Request under How to block and then click OK
  • Expand the rule and select the rule with the pattern .*autodiscover\.json.*\@.*Powershell.* and click Edit under Conditions.
  • Change the Condition input from {URL} to {REQUEST_URI}

As additional prevention measures, the company is urging companies to enforce multi-factor authentication (MFA), disable legacy authentication, and educate users about not accepting unexpected two-factor authentication (2FA) prompts.

“Microsoft Exchange is a juicy target for threat actors to exploit for two primary reasons,” Travis Smith, vice president of malware threat research at Qualys, told The Hacker News.

“First, Exchange […] being directly connected to the internet creates an attack surface which is accessible from anywhere in the world, drastically increasing its risk of being attacked. Secondly, Exchange is a mission critical function – organizations can’t just unplug or turn off email without severely impacting their business in a negative way.”

Found this article interesting? Follow THN on Facebook, Twitter and LinkedIn to read more exclusive content we post.

Related news

Microsoft Patch Tuesday June 2023: Edge type confusion, Git RCE, OneNote Spoofing, PGM RCE, Exchange RCE, SharePoint EoP

Hello everyone! This episode will be about Microsoft Patch Tuesday for June 2023, including vulnerabilities that were added between May and June Patch Tuesdays. As usual, I use my open source Vulristics project to analyse and prioritize vulnerabilities. I took the comments about the vulnerabilities from the Qualys, Tenable, Rapid7, ZDI Patch Tuesday reviews. This time there […]

New Wave of Cyberattacks Targeting MS Exchange Servers

By Waqas Cybercriminals are leveraging two exploit chains (ProxyNotShell/OWASSRF) to target Microsoft Exchange servers, as warned by Bitdefender Labs. This is a post from HackRead.com Read the original post: New Wave of Cyberattacks Targeting MS Exchange Servers

Rackspace Ransomware Incident Highlights Risks of Relying on Mitigation Alone

Organizations often defer patching because of business disruption fears — but that didn't work out very well for Rackspace's Hosted Exchange service.

Rackspace: Ransomware Attack Bypassed ProxyNotShell Mitigations

The hosting provider had not applied Microsoft's new patch due to publicly reported issues with the update.

Ransomware Hackers Using New Way to Bypass MS Exchange ProxyNotShell Mitigations

Threat actors affiliated with a ransomware strain known as Play are leveraging a never-before-seen exploit chain that bypasses blocking rules for ProxyNotShell flaws in Microsoft Exchange Server to achieve remote code execution (RCE) through Outlook Web Access (OWA). "The new exploit method bypasses URL rewrite mitigations for the Autodiscover endpoint," CrowdStrike researchers Brian Pitchford,

Microsoft Patch Tuesday November 2022: Exchange ProxyNotShell RCE, JScript9, MoTW, OpenSSL, Edge, CNG, Print Spooler

Hello everyone! This episode will be about Microsoft Patch Tuesday for November 2022, including vulnerabilities that were added between October and November Patch Tuesdays. As usual, I use my open source Vulristics project to create the report. Alternative video link (for Russia): https://vk.com/video-149273431_456239107 The most important news of this Patch Tuesday was a release of patches […]

Microsoft Issues Patches to Fix 6 Active 0-Day Windows Vulnerabilities

By Deeba Ahmed Microsoft has urged Windows Administrators to install the updates urgently so make sure you have the latest patches installed! This is a post from HackRead.com Read the original post: Microsoft Issues Patches to Fix 6 Active 0-Day Windows Vulnerabilities

Install Latest Windows Update ASAP! Patches Issued for 6 Actively Exploited Zero-Days

Microsoft's latest round of monthly security updates has been released with fixes for 68 vulnerabilities spanning its software portfolio, including patches for six actively exploited zero-days. 12 of the issues are rated Critical, two are rated High, and 55 are rated Important in severity. This also includes the weaknesses that were closed out by OpenSSL the previous week. Also separately

Microsoft Patch Tuesday October 2022: Exchange ProxyNotShell RCE, Windows COM+ EoP, AD EoP, Azure Arc Kubernetes EoP

Hello everyone! This episode will be about Microsoft Patch Tuesday for October 2022, including vulnerabilities that were added between September and October Patch Tuesdays. As usual, I use my open source Vulristics project to create the report. All vulnerabilities: 105Urgent: 2Critical: 1High: 29Medium: 71Low: 2 Let’s take a look at the most interesting vulnerabilities: Two […]

Update now! October patch Tuesday fixes actively used zero-day...but not the one you expected

Categories: Exploits and vulnerabilities Categories: News Tags: Microsoft Tags: Apple Tags: Google Tags: Android Tags: Samsung Tags: Xiaomi Tags: Adobe Tags: SAP Tags: VMWare Tags: Fortinet Tags: CVE-2022-41033 Tags: CVE-2022-41040 Tags: zero-day No fix for ProxyNotShell (Read more...) The post Update now! October patch Tuesday fixes actively used zero-day...but not the one you expected appeared first on Malwarebytes Labs.

Microsoft Addresses Zero-Days, but Exchange Server Exploit Chain Remains Unpatched

The computing giant didn't fix ProxyNotLogon in October's Patch Tuesday, but it disclosed a rare 10-out-of-10 bug and patched two other zero-days, including one being exploited.

Microsoft Issues Improved Mitigations for Unpatched Exchange Server Vulnerabilities

Microsoft on Friday disclosed it has made more improvements to the mitigation method offered as a means to prevent exploitation attempts against the newly disclosed unpatched security flaws in Exchange Server. To that end, the tech giant has revised the blocking rule in IIS Manager from ".*autodiscover\.json.*Powershell.*" to "(?=.*autodiscover\.json)(?=.*powershell)." The list of

Threat Source newsletter (Oct. 6, 2022) — Continuing down the Privacy Policy rabbit hole

By Jon Munshaw.  Welcome to this week’s edition of the Threat Source newsletter.  As I wrote about last week, I’ve been diving a lot into apps’ privacy policies recently. And I was recently made aware of a new type of app I never knew existed — family trackers.  There are countless mobile apps for parents to track their children or other family members based on their location, phone usage, and even driving speed. As an anxious soon-to-be-parent, this sounds intriguing to me — it’d be a supped-up version of Find my Friends on Apple devices so I’d never have to ask my teenager (granted, I’m many years away from being at that stage of my life) when they were coming home or where they were.  Just as with all other types of mobile apps, there are pitfalls, though.   Life360, one of the most popular of these types of apps and even tells users what their maximum driving speed was on a given trip, was found in December 2021 to be selling precise location data on its users, potentia...

Threat Source newsletter (Oct. 6, 2022) — Continuing down the Privacy Policy rabbit hole

Any time we welcome this software and hardware into our homes and on our devices, it’s worth considering what sacrifices we might be making elsewhere.

Mitigation for Exchange Zero-Days Bypassed! Microsoft Issues New Workarounds

Microsoft has revised its mitigation measures for the newly disclosed and actively exploited zero-day flaws in Exchange Server after it was found that they could be trivially bypassed. The two vulnerabilities, tracked as CVE-2022-41040 and CVE-2022-41082, have been codenamed ProxyNotShell due to similarities to another set of flaws called ProxyShell, which the tech giant resolved last year.

ProxyNotShell – the New Proxy Hell?

Nicknamed ProxyNotShell, a new exploit used in the wild takes advantage of the recently published Microsoft Server-Side Request Forgery (SSRF) vulnerability CVE-2022-41040 and a second vulnerability, CVE-2022-41082 that allows Remote Code Execution (RCE) when PowerShell is available to unidentified attackers. Based on ProxyShell, this new zero-day abuse risk leverage a chained attack similar to

CVE-2022-41082

Microsoft Exchange Server Remote Code Execution Vulnerability.

CVE-2022-41040

Microsoft Exchange Server Elevation of Privilege Vulnerability.

Worried About the Exchange Zero-Day? Here's What to Do

While organizations wait for an official patch for the two zero-day flaws in Microsoft Exchange, they should scan their networks for signs of exploitation and apply these mitigations.

Threat Advisory: Microsoft warns of actively exploited vulnerabilities in Exchange Server

Cisco Talos has released new coverage to detect and prevent the exploitation of two recently disclosed vulnerabilities collectively referred to as "ProxyNotShell," affecting Microsoft Exchange Servers 2013, 2016 and 2019. One of these vulnerabilities could allow an attacker to execute remote code on the targeted server. Limited exploitation of these vulnerabilities in the wild has been reported. CVE-2022-41040 is a Server Side Request Forgery (SSRF) vulnerability, while CVE-2022-41082 enables Remote Code Execution (RCE) when PowerShell is accessible to the attackers. While no fixes or patches are available yet, Microsoft has provided mitigations for on-premises Microsoft Exchange users on Sept. 29, 2022. Even organizations that use Exchange Online may still be affected if they run a hybrid server. Cisco Talos is closely monitoring the recent reports of exploitation attempts against these vulnerabilities and strongly recommends users implement mitigation steps while waiting for securit...

Threat Advisory: Microsoft warns of actively exploited vulnerabilities in Exchange Server

Cisco Talos has released new coverage to detect and prevent the exploitation of two recently disclosed vulnerabilities collectively referred to as "ProxyNotShell," affecting Microsoft Exchange Servers 2013, 2016 and 2019. One of these vulnerabilities could allow an attacker to execute remote code on the targeted server. Limited exploitation of these vulnerabilities in the wild has been reported. CVE-2022-41040 is a Server Side Request Forgery (SSRF) vulnerability, while CVE-2022-41082 enables Remote Code Execution (RCE) when PowerShell is accessible to the attackers. While no fixes or patches are available yet, Microsoft has provided mitigations for on-premises Microsoft Exchange users on Sept. 29, 2022. Even organizations that use Exchange Online may still be affected if they run a hybrid server. Cisco Talos is closely monitoring the recent reports of exploitation attempts against these vulnerabilities and strongly recommends users implement mitigation steps while waiting for securit...

Microsoft Confirms Two 0-Days Being Exploited Against Exchange Servers

By Deeba Ahmed The latest attack against Exchange servers utilizes at least two new flaws (CVE-2022-41040, CVE-2022-41082) that have been assigned CVSS scores of 6.3 and 8.8. This is a post from HackRead.com Read the original post: Microsoft Confirms Two 0-Days Being Exploited Against Exchange Servers

Microsoft Confirms Two 0-Days Being Exploited Against Exchange Servers

By Deeba Ahmed The latest attack against Exchange servers utilizes at least two new flaws (CVE-2022-41040, CVE-2022-41082) that have been assigned CVSS scores of 6.3 and 8.8. This is a post from HackRead.com Read the original post: Microsoft Confirms Two 0-Days Being Exploited Against Exchange Servers

Microsoft: Two New 0-Day Flaws in Exchange Server

Microsoft Corp. is investigating reports that attackers are exploiting two previously unknown vulnerabilities in Exchange Server, a technology many organizations rely on to send and receive email. Microsoft says it is expediting work on software patches to plug the security holes. In the meantime, it is urging a subset of Exchange customers to enable a setting that could help mitigate ongoing attacks.

Microsoft: Two New 0-Day Flaws in Exchange Server

Microsoft Corp. is investigating reports that attackers are exploiting two previously unknown vulnerabilities in Exchange Server, a technology many organizations rely on to send and receive email. Microsoft says it is expediting work on software patches to plug the security holes. In the meantime, it is urging a subset of Exchange customers to enable a setting that could help mitigate ongoing attacks.

Microsoft Confirms Pair of Blindsiding Exchange Zero-Days, No Patch Yet

The "ProxyNotShell" security vulnerabilities can be chained for remote code execution and total takeover of corporate email platforms.

Two new Exchange Server zero-days in the wild

Categories: Exploits and vulnerabilities Categories: News Tags: Exchange Tags: ProxyShell Tags: remote PowerShell Tags: web shell Tags: CVE-2022-41040 Tags: CVE-2022-41082 Tags: SSRF Tags: RCE Two ProxyShell-like vulnerabilities are being used to exploit Microsoft Exchange Servers (Read more...) The post Two new Exchange Server zero-days in the wild appeared first on Malwarebytes Labs.

Two new Exchange Server zero-days in the wild

Categories: Exploits and vulnerabilities Categories: News Tags: Exchange Tags: ProxyShell Tags: remote PowerShell Tags: web shell Tags: CVE-2022-41040 Tags: CVE-2022-41082 Tags: SSRF Tags: RCE Two ProxyShell-like vulnerabilities are being used to exploit Microsoft Exchange Servers (Read more...) The post Two new Exchange Server zero-days in the wild appeared first on Malwarebytes Labs.

Microsoft Confirms 2 New Exchange Zero-Day Flaws Being Used in the Wild

Microsoft officially disclosed it investigating two zero-day security vulnerabilities impacting Exchange Server 2013, 2016, and 2019 following reports of in-the-wild exploitation. "The first vulnerability, identified as CVE-2022-41040, is a Server-Side Request Forgery (SSRF) vulnerability, while the second, identified as CVE-2022-41082, allows remote code execution (RCE) when PowerShell is

Microsoft Confirms 2 New Exchange Zero-Day Flaws Being Used in the Wild

Microsoft officially disclosed it investigating two zero-day security vulnerabilities impacting Exchange Server 2013, 2016, and 2019 following reports of in-the-wild exploitation. "The first vulnerability, identified as CVE-2022-41040, is a Server-Side Request Forgery (SSRF) vulnerability, while the second, identified as CVE-2022-41082, allows remote code execution (RCE) when PowerShell is

Customer Guidance for Reported Zero-day Vulnerabilities in Microsoft Exchange Server

Summary Microsoft is investigating two reported zero-day vulnerabilities affecting Microsoft Exchange Server 2013, 2016, and 2019. The first vulnerability, identified as CVE-2022-41040, is a Server-Side Request Forgery (SSRF) vulnerability, while the second, identified as CVE-2022-41082, allows remote code execution (RCE) when PowerShell is accessible to the attacker.   At this time, Microsoft is aware of limited … Customer Guidance for Reported Zero-day Vulnerabilities in Microsoft Exchange Server Read More »

Customer Guidance for Reported Zero-day Vulnerabilities in Microsoft Exchange Server

Summary Microsoft is investigating two reported zero-day vulnerabilities affecting Microsoft Exchange Server 2013, 2016, and 2019. The first vulnerability, identified as CVE-2022-41040, is a Server-Side Request Forgery (SSRF) vulnerability, while the second, identified as CVE-2022-41082, allows remote code execution (RCE) when PowerShell is accessible to the attacker.   At this time, Microsoft is aware of limited … Customer Guidance for Reported Zero-day Vulnerabilities in Microsoft Exchange Server Read More »