CVE-2020-4044
The xrdp-sesman service before version 0.9.13.1 can be crashed by connecting over port 3350 and supplying a malicious payload.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.40%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.40% probability · 83th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-121
- Affected
- neutrinolabs/xrdp
- Source
- security-advisories@github.com
References
- 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/0c791d073d0eb344ee7aaafd221513dc9226762cPatch, Third Party Advisory
- https://github.com/neutrinolabs/xrdp/releases/tag/v0.9.13.1Release Notes, Third Party Advisory
- https://github.com/neutrinolabs/xrdp/security/advisories/GHSA-j9fv-6fwf-p3g4Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/08/msg00015.html
- https://www.debian.org/security/2020/dsa-4737
- 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/0c791d073d0eb344ee7aaafd221513dc9226762cPatch, Third Party Advisory
- https://github.com/neutrinolabs/xrdp/releases/tag/v0.9.13.1Release Notes, Third Party Advisory
- https://github.com/neutrinolabs/xrdp/security/advisories/GHSA-j9fv-6fwf-p3g4Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/08/msg00015.html
- https://www.debian.org/security/2020/dsa-4737
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.