CVE-2021-35211
Serv-U Remote Memory Escape Vulnerability
Microsoft discovered a remote code execution (RCE) vulnerability in the SolarWinds Serv-U product utilizing a Remote Memory Escape Vulnerability. If exploited, a threat actor may be able to gain privileged access to the machine hosting Serv-U Only. SolarWinds Serv-U Managed File Transfer and Serv-U Secure FTP for Windows before 15.2.3 HF2 are affected by this vulnerability.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Serv-U Remote Memory Escape Vulnerability
Microsoft discovered a remote code execution (RCE) vulnerability in the SolarWinds Serv-U product utilizing a Remote Memory Escape Vulnerability. If exploited, a threat actor may be able to gain privileged access to the machine hosting Serv-U Only. SolarWinds Serv-U Managed File Transfer and Serv-U Secure FTP for Windows before 15.2.3 HF2 are affected by this vulnerability.
- Record
CVE-2021-35211- CVSS 3.1
- 9.0 Critical
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
EUVDEUVD-2021-21854
Microsoft discovered a remote code execution (RCE) vulnerability in the SolarWinds Serv-U product utilizing a Remote Memory Escape Vulnerability. If exploited, a threat actor may be able to gain privileged access to the machine hosting Serv-U Only. SolarWinds Serv-U Managed File Transfer and Serv-U Secure FTP for Windows before 15.2.3 HF2 are affected by this vulnerability.
- Record
EUVD-2021-21854- CVSS 3.1
- 9.0 Critical
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-cpmg-9xq8-3934
Microsoft discovered a remote code execution (RCE) vulnerability in the SolarWinds Serv-U product...
Microsoft discovered a remote code execution (RCE) vulnerability in the SolarWinds Serv-U product utilizing a Remote Memory Escape Vulnerability. If exploited, a threat actor may be able to gain privileged access to the machine hosting Serv-U Only. SolarWinds Serv-U Managed File Transfer and Serv-U Secure FTP for Windows before 15.2.3 HF2 are affected by this vulnerability.
- Record
GHSA-cpmg-9xq8-3934- CVSS 3.1
- 10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-668, CWE-787
- Updated
- 2026-11-02
CISA KEV No score
SolarWinds Serv-U Remote Code Execution Vulnerability
SolarWinds Serv-U contains an unspecified memory escape vulnerability which can allow for remote code execution.
- Record
CVE-2021-35211- Weakness
- CWE-787
- Updated
- 2026-11-02
NVD
Microsoft discovered a remote code execution (RCE) vulnerability in the SolarWinds Serv-U product utilizing a Remote Memory Escape Vulnerability. If exploited, a threat actor may be able to gain privileged access to the machine hosting Serv-U Only. SolarWinds Serv-U Managed File Transfer and Serv-U Secure FTP for Windows before 15.2.3 HF2 are affected by this vulnerability.
- Record
CVE-2021-35211- CVSS 3.1
- 9.0 Critical
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H - CVSS 3.1
- 10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - CVSS 2.0
- 10.0 High
AV:N/AC:L/Au:N/C:C/I:C/A:C - Weakness
- CWE-787
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | NattiSamson/Serv-U-CVE-2021-35211 | 2021-09-30 |
| PoC in GitHub | 0xhaggis/CVE-2021-35211 | 2021-10-24 |
| PoC in GitHub | BishopFox/CVE-2021-35211 | 2022-01-14 |
| Nuclei | SolarWinds Serv-U FTP - Remote Code Execution |
History
| Recorded | Changed | Sources |
|---|---|---|
| exploitation, exploits | ||
| first indexed | CVE List, EUVD, GitHub Advisories, CISA KEV, Nuclei, NVD, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-35211 is a critical vulnerability (CVSS 9.0) in Solarwinds Serv-u, published July 14, 2021. CISA lists it as known to be exploited, since November 3, 2021. EUVD reports exploitation since November 3, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 91.2%, the 99th percentile. No source names a fixed version.
References
solarwinds.com/trust-center/security-advisories/cve-2021-35211
microsoft.com/security/blog/2021/07/13/microsoft-discovers-threat-actor-targeting-solarwinds-serv-u-software-with-0-day-exploit
cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-35211
nvd.nist.gov/vuln/detail/CVE-2021-35211
github.com/advisories/GHSA-cpmg-9xq8-3934