Microsoft Remote Desktop Services Remote Code Execution
CVE-2019-0708 is a critical-severity use after free vulnerability in Windows from Microsoft, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Windows versions: 7 for 32-bit Systems Service Pack 1; 7 for x64-based Systems Service Pack 1. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on November 3, 2021, which means attacks have been observed in the wild, including in ransomware campaigns.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Check which version of Windows you run against the affected versions below, and install the vendor's latest release.
- CISA's required action: Apply updates per vendor instructions.
- Read the advisory on huawei.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Microsoft | Windows | 7 for 32-bit Systems Service Pack 1; 7 for x64-based Systems Service Pack 1 | Not stated |
| Microsoft | Windows Server | 2008 R2 for Itanium-Based Systems Service Pack 1; 2008 R2 for x64-based Systems Service Pack 1; 2008 for 32-bit Systems Service Pack 2 (Core installation); 2008 for Itanium-Based Systems Service Pack 2; 2008 for 32-bit Systems Service Pack 2; 2008 for x64-based Systems Service Pack 2 | Not stated |
| Microsoft | Windows 7 | Not specified in the record | Not stated |
| Microsoft | Windows Server 2008 | r2 | Not stated |
| Siemens | Axiom Multix M Firmware | Not specified in the record | Not stated |
| Siemens | Axiom Vertix Md Trauma Firmware | Not specified in the record | Not stated |
| Siemens | Axiom Vertix Solitaire M Firmware | Not specified in the record | Not stated |
| Siemens | Mobilett Xp Digital Firmware | Not specified in the record | Not stated |
| Siemens | Multix Pro Acss P Firmware | Not specified in the record | Not stated |
| Siemens | Multix Pro P Firmware | Not specified in the record | Not stated |
| Siemens | Multix Pro Firmware | Not specified in the record | Not stated |
| Siemens | Multix Pro Acss Firmware | Not specified in the record | Not stated |
| Siemens | Multix Pro Navy Firmware | Not specified in the record | Not stated |
| Siemens | Multix Swing Firmware | Not specified in the record | Not stated |
| Siemens | Multix Top Firmware | Not specified in the record | Not stated |
| Siemens | Multix Top Acss Firmware | Not specified in the record | Not stated |
| Siemens | Multix Top P Firmware | Not specified in the record | Not stated |
| Siemens | Multix Top Acss P Firmware | Not specified in the record | Not stated |
| Siemens | Vertix Solitaire Firmware | Not specified in the record | Not stated |
| Siemens | Atellica Solution Firmware | Not specified in the record | Not stated |
| Siemens | Aptio Firmware | Not specified in the record | Not stated |
| Siemens | Streamlab Firmware | Not specified in the record | Not stated |
| Siemens | Centralink Firmware | Not specified in the record | Not stated |
| Siemens | Viva E Firmware | Not specified in the record | Not stated |
| Siemens | Viva Twin Firmware | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE; 35 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | NVD |
| CVSS 3.1 | 9.8 | Critical | CISA (ADP) |
| CVSS 2.0 | 10.0 | High | NVD |
Official description
A remote code execution vulnerability exists in Remote Desktop Services formerly known as Terminal Services when an unauthenticated attacker connects to the target system using RDP and sends specially crafted requests, aka 'Remote Desktop Services Remote Code Execution Vulnerability'.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- packetstormsecurity.com/files/155389/Microsoft-Windows-7-x86-BlueKeep-RDP-Use-After-Free.htmlThird Party Advisory, VDB Entry
- cert-portal.siemens.com/productcert/pdf/ssa-166360.pdfThird Party Advisory
- cert-portal.siemens.com/productcert/pdf/ssa-406175.pdfThird Party Advisory
- cert-portal.siemens.com/productcert/pdf/ssa-433987.pdfThird Party Advisory
- cert-portal.siemens.com/productcert/pdf/ssa-616199.pdfThird Party Advisory
- cert-portal.siemens.com/productcert/pdf/ssa-832947.pdfThird Party Advisory
- cert-portal.siemens.com/productcert/pdf/ssa-932041.pdfThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-0708US Government Resource
Technical write-ups (may include proof of concept)
- packetstormsecurity.com/files/153133/Microsoft-Windows-Remote-Desktop-BlueKeep-Denial-Of-Service.htmlExploit, Third Party Advisory, VDB Entry
- packetstormsecurity.com/files/153627/Microsoft-Windows-RDP-BlueKeep-Denial-Of-Service.htmlExploit, Third Party Advisory, VDB Entry
- packetstormsecurity.com/files/154579/BlueKeep-RDP-Remote-Windows-Kernel-Use-After-Free.htmlExploit, Third Party Advisory, VDB Entry
- packetstormsecurity.com/files/162960/Microsoft-RDP-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
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