Elefant Software Updater: Time-of-check Time-of-use (TOCTOU) Race Condition
CVE-2024-50592 is a high-severity time-of-check time-of-use (TOCTOU) race condition vulnerability in Elefant Software Updater from HASOMED, with a CVSS 3.1 base score of 7.0 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 1.4.2.1811 as the first without the flaw, so updating Elefant 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 Elefant Software Updater to 1.4.2.1811 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| HASOMED | Elefant Software Updater | <1.4.2.1811; before 1.4.2.1811 | 1.4.2.1811 |
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
- HighSuccess depends on conditions outside the attacker's control.
- 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:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official description
An attacker with local access the to medical office computer can escalate his Windows user privileges to "NT AUTHORITY\SYSTEM" by exploiting a race condition in the Elefant Update Service during the repair or update process. When using the repair function, the service queries the server for a list of files and their hashes. In addition, instructions to execute binaries to finalize the repair process are included. The executables are executed as "NT AUTHORITY\SYSTEM" after they are copied over to the user writable installation folder (C:\Elefant1). This means that a user can overwrite either "PostESUUpdate.exe" or "Update_OpenJava.exe" in the time frame after the copy and before the execution of the final repair step. The overwritten executable is then executed as "NT AUTHORITY\SYSTEM".
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Time-of-check Time-of-use (TOCTOU) Race Condition
The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
How developers prevent this class of flaw
- The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.
- When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.
- Limit the interleaving of operations on files from multiple processes.
More Time-of-check Time-of-use (TOCTOU) Race Condition vulnerabilities (CWE-367)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Elefant Software Updater
- 7.8 High severity
Recent Time-of-check Time-of-use (TOCTOU) Race Condition vulnerabilities
- 7.5 High severity
- 8.3 High severity
- 9.8 Critical severity
- 7.0 High severity
- 7.0 High severity
- 7.0 High severity
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