CVE-2020-4044: Local users can perform a buffer overflow attack against the xrdp-sesman service and then impersonate it
First published: Tue Jun 30 2020(Updated: )
The xrdp-sesman service before version 0.9.13.1 can be crashed by connecting over port 3350 and supplying a malicious payload. Once the xrdp-sesman process is dead, an unprivileged attacker on the server could then proceed to start their own imposter sesman service listening on port 3350. This will allow them to capture any user credentials that are submitted to XRDP and approve or reject arbitrary login credentials. For xorgxrdp sessions in particular, this allows an unauthorized user to hijack an existing session. This is a buffer overflow attack, so there may be a risk of arbitrary code execution as well.
Credit: security-advisories@github.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| debian/xrdp | 0.9.9-1+deb10u1 0.9.9-1+deb10u3 0.9.21.1-1~deb11u1 0.9.21.1-1 | |
| xrdp | <0.9.13.1 |
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Reference Links
- https://security-tracker.debian.org/tracker/CVE-2020-4044
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-4044
- https://github.com/neutrinolabs/xrdp/security/advisories/GHSA-j9fv-6fwf-p3g4
- https://github.com/neutrinolabs/xrdp/commit/e593f58a82bf79b556601ae08e9e25e366a662fb
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=964573
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00036.html
- http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00037.html
- https://github.com/neutrinolabs/xrdp/commit/0c791d073d0eb344ee7aaafd221513dc9226762c
- https://github.com/neutrinolabs/xrdp/releases/tag/v0.9.13.1
- https://lists.debian.org/debian-lts-announce/2020/08/msg00015.html
- https://www.debian.org/security/2020/dsa-4737
Frequently Asked Questions
What is CVE-2020-4044?
CVE-2020-4044 is a vulnerability in the xrdp-sesman service that allows an unprivileged attacker to crash the service and start their own imposter sesman service.
How does CVE-2020-4044 affect the xrdp-sesman service?
CVE-2020-4044 affects the xrdp-sesman service before version 0.9.13.1, allowing for a DoS attack and potential takeover of the service.
What is the severity of CVE-2020-4044?
CVE-2020-4044 has a severity rating of 7.8 (High).
How can I fix CVE-2020-4044?
To fix CVE-2020-4044, update your xrdp-sesman service to version 0.9.13.1 or higher.
Are there any references for CVE-2020-4044?
Yes, you can find more information about CVE-2020-4044 at the following references: - [OpenSUSE Security Announcement 2020-07](http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00036.html) - [OpenSUSE Security Announcement 2020-08](http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00037.html) - [GitHub Commit](https://github.com/neutrinolabs/xrdp/commit/0c791d073d0eb344ee7aaafd221513dc9226762c)
- collector/debian-bugs
- alias/CVE-2020-4044
- collector/security-tracker-debian
- agent/type
- collector/mitre-cve
- source/MITRE
- agent/last-modified-date
- agent/severity
- agent/author
- agent/weakness
- agent/references
- agent/remedy
- agent/title
- agent/description
- agent/first-publish-date
- agent/event
- agent/source
- agent/tags
- agent/softwarecombine
- collector/nvd-index
- agent/software-canonical-lookup-request
- package-manager/debian
- vendor/neutrinolabs
- canonical/xrdp