Critical Out-Of-Bounds Read Vulnerability in rdesktop Package

rdesktop Updated 02 Oct 2025

Summary

05/02/2019

Disclosed on

N/A

Severity

Yes i

Fix available

High

Severity

7.5

CVSS Score

ALPINE-CVE-2018-8792: rdesktop versions up to and including v1.8.3 contain an Out-Of-Bounds Read in function cssp_read_tsrequest() that results in a Denial of Service (segfault). Affects rdesktop versions < 1.8.6-r0. Fixed in 1.8.6-r0. How to fix ↓

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Background

rdesktop is an open-source client for the Remote Desktop Protocol (RDP), allowing users to connect to Windows desktops remotely. It is widely used for its simplicity and effectiveness in providing remote access. However, certain versions of rdesktop are vulnerable to an Out-Of-Bounds Read issue, which can lead to Denial of Service (DoS) attacks.

Vulnerability Detail

The vulnerability, identified as CVE-2018-8792, exists in rdesktop versions up to and including v1.8.3. It arises from an Out-Of-Bounds Read in the function cssp_read_tsrequest(). This flaw can be exploited to cause a segmentation fault (segfault), resulting in a Denial of Service. Attackers can leverage this vulnerability to disrupt services, making the application unavailable to legitimate users.

How To Fix

Minimum fixed version

1.8.6-r0

This is the first release that contains the fix.

sudo apk add --upgrade rdesktop

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Workaround

If you cannot immediately update the package, consider restricting access to the rdesktop service or using alternative remote desktop solutions until the update can be applied.

Conclusion

The rdesktop package has a critical vulnerability that can lead to Denial of Service. It is essential to update to the patched version to mitigate risks. Users should also consider using Vulert to monitor for vulnerabilities in their applications.

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