Splashtop Software Updater: Creation of Temporary File in Directory with Insecure Permissions
CVE-2023-3181 is a high-severity creation of temporary file in directory with insecure permissions vulnerability in Splashtop Software Updater from Splashtop, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists version 1.5.6.21 as the first without the flaw, so updating Splashtop Software Updater to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.18% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Splashtop Software Updater to 1.5.6.21 or a later version.
- Update Mirroring360 Receiver to 2.4.0.1 or a later version.
- Update Mirroring360 Sender to 1.3.0.0 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Splashtop | Splashtop Software Updater | before 1.5.6.21 | 1.5.6.21 |
| Splashtop | Mirroring360 Receiver | before 2.4.0.1 | 2.4.0.1 |
| Splashtop | Mirroring360 Sender | before 1.3.0.0 | 1.3.0.0 |
| Splashtop | Splashtop | before 3.5.6.0; before 3.5.8.0 | 3.5.6.0, 3.5.8.0 |
| Splashtop | Splashtop For Rmm | before 3.5.8.0 | 3.5.8.0 |
| Splashtop | Streamer | before 3.5.6.0 | 3.5.6.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA (google.com) |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
The C:\Program Files (x86)\Splashtop\Splashtop Software Updater\uninst.exe process creates a folder at C:\Windows\Temp~nsu.tmp and copies itself to it as Au_.exe. The C:\Windows\Temp~nsu.tmp\Au_.exe file is automatically launched as SYSTEM when the system reboots or when a standard user runs an MSI repair using Splashtop Streamer’s Windows Installer. Since the C:\Windows\Temp~nsu.tmp folder inherits permissions from C:\Windows\Temp and Au_.exe is susceptible to DLL hijacking, standard users can write a malicious DLL to it and elevate their privileges.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Creation of Temporary File in Directory with Insecure Permissions
The product creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file.
How developers prevent this class of flaw
- Many contemporary languages have functions which properly handle this condition. Older C temp file functions are especially susceptible.
- Try to store sensitive tempfiles in a directory which is not world readable -- i.e., per-user directories.
- Avoid using vulnerable temp file functions.
More Creation of Temporary File in Directory with Insecure Permissions vulnerabilities (CWE-379)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- github.com/mandiant/Vulnerability-Disclosures/blob/master/2023/MNDT-2023-0015.mdThird Party Advisory
Recent Creation of Temporary File in Directory with Insecure Permissions vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
Spotted an error? Tell us.