PoC exploit code for ProxyNotShell Microsoft Exchange bugs released online
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2022-41040 +1 in the same advisory: …41082 | Server-Side Request Forgery in Microsoft Exchange Server (ProxyNotShell) CVE-2022-41040 is a server-side request forgery (SSRF, CWE-918) vulnerability in Microsoft Exchange Server, publicly tracked under the name "ProxyNotShell" together with CVE-2022-41082. It is triggered when an attacker sends crafted HTTP requests to exposed Exchange web endpoints (such as Autodiscover), causing the server to issue attacker-influenced requests to itself. On its own the SSRF coerces authenticated server-side requests, but when chained with the CVE-2022-41082 remote code execution flaw it gives the attacker code execution on the Exchange server, typically followed by web shells, data access, and — in observed campaigns — ransomware deployment. Organizations running on-premises Microsoft Exchange Server are affected; the source data lists only Microsoft Exchange Server and does not specify affected version ranges, and hosted Exchange Online is a separate product not listed here. The vulnerability is being actively exploited in the wild: it was added to CISA's Known Exploited Vulnerabilities catalog on 2022-09-30 with known ransomware use, and EPSS assigns it a 100% probability of exploitation within 30 days; no public PoC is listed. Do: Apply Microsoft's Exchange Server security updates per vendor instructions immediately, as required by the CISA KEV catalog. As interim mitigation, restrict or block untrusted internet access to Exchange web endpoints (e.g., Autodiscover, OWA, ECP), and review IIS logs for suspicious crafted requests indicating SSRF or the chained CVE-2022-41082 exploitation. Given documented ransomware use, prioritize any internet-facing Exchange server and hunt for web shells and post-exploitation activity. | 8.8 group max | 100% | KEV ransomware PoC |
| mass≈250,000+ internet-exposed Exchange servers (public scans of exposed OWA/ECP/Exchange endpoints) |
Full article346 words · extracted from securityaffairs.com · click to collapse
Pierluigi Paganini
November 20, 2022
Proof-of-concept exploit code for two actively exploited Microsoft Exchange ProxyNotShell flaws released online.
Proof-of-concept exploit code has been released online for two actively exploited vulnerabilities in Microsoft Exchange, known as ProxyNotShell.
The two flaws are:
- CVE-2022-41040 – Microsoft Exchange Server Elevation of Privilege Vulnerability
- CVE-2022-41082 – Microsoft Exchange Server Remote Code Execution Vulnerability
they impact Exchange Server 2013, 2016, and 2019, an authenticated attacker can trigger them to elevate privileges to run PowerShell in the context of the system and gain arbitrary or remote code execution on vulnerable servers.
Cybersecurity firm GreyNoise confirmed that threat actors are attempting to exploit the flaws since late September, Bleeping Computer reported.
Microsoft addressed both vulnerabilities with the release of Patch Tuesday updates for November 2022 security updates.
This week the popular researcher Will Dormann confirmed that PoC exploit code released by the security researcher Janggggg, which was exploited by threat actors in the wild, works against Exchange Server 2016 and 2019, and even against 2013 with some modifications. The expert demonstrated how to exploit the bug to execute calc.exe as SYSTEM.
Hmm, I'm not sure what I did wrong the first time around, but Exchange 2016 seems to work just fine with this PoC as well. It's perhaps just Exchange 2013 that requires a tweak. pic.twitter.com/nYJ0dC9zzL
— Will Dormann (@wdormann) November 18, 2022
Microsoft urges its customers to install the updates immediately to be protected against attacks exploring these flaws. The IT giant confirmed that they are aware of active exploits of related vulnerabilities that have been used in limited targeted attacks.
“Because we are aware of active exploits of related vulnerabilities (limited targeted attacks), our recommendation is to install these updates immediately to be protected against these attacks.” states Microsoft.
“Mitigations are not actual code fixes of specific vulnerabilities. Please install the November 2022 (or later) SU on your Exchange servers to address CVE-2022-41040 and CVE-2022-41082.”
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Text extracted automatically; images, tables and formatting may be missing. Original: https://securityaffairs.com/138768/hacking/proxynotshell-microsoft-exchange-poc.html