Skip to content
Noroxi
CVE-2020-4044· NVD / CVE Program· CNA GitHub_M

Local users can perform a buffer overflow attack against the xrdp-sesman service and then impersonate it

Noroxi assessment

Priority: Monitor (action score 32/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 2.4% (FIRST EPSS); higher than 83.8% of all records.
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: xrdp (Debian:10) 0.9.9-1+deb10u1; xrdp (Debian:12) 0.9.12-1.1; xrdp (Debian:9) 0.9.1-9+deb9u4.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to xrdp (Debian:10) 0.9.9-1+deb10u1; xrdp (Debian:12) 0.9.12-1.1; xrdp (Debian:9) 0.9.1-9+deb9u4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Jun 30, 2020
Updated
Jun 16, 2026
EPSS
2.4% · 83th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 2.4%

CNA vs NVD score

NVD
7.8
CNA · GitHub_M
7.5
0.3 point gap

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2020-4044

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for neutrinolabs records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
neutrinolabsxrdp

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • neutrinolabs xrdpbefore 0.9.13.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • neutrinolabs xrdp

    • < 0.9.13.1affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:10xrdpbefore 0.9.9-1+deb10u10.9.9-1+deb10u1
Debian:12xrdpbefore 0.9.12-1.10.9.12-1.1
Debian:9xrdpbefore 0.9.1-9+deb9u40.9.1-9+deb9u4
openSUSE:Leap 15.1xrdpbefore 0.9.6-lp151.4.6.10.9.6-lp151.4.6.1
openSUSE:Leap 15.2xrdpbefore 0.9.13.1-lp152.3.3.10.9.13.1-lp152.3.3.1
openSUSE:Tumbleweedxrdpbefore 0.9.15-2.20.9.15-2.2
SUSE:HPE Helion OpenStack 8xrdpbefore 0.9.0~git.1456906198.f422461-21.27.10.9.0~git.1456906198.f422461-21.27.1
SUSE:Linux Enterprise Module for Basesystem 15 SP1xrdpbefore 0.9.6-4.8.10.9.6-4.8.1
SUSE:Linux Enterprise Module for Basesystem 15 SP2xrdpbefore 0.9.13.1-4.3.10.9.13.1-4.3.1
SUSE:Linux Enterprise Server 12 SP5xrdpbefore 0.9.10-3.3.10.9.10-3.3.1
SUSE:OpenStack Cloud 7xrdpbefore 0.9.0~git.1456906198.f422461-16.20.10.9.0~git.1456906198.f422461-16.20.1

Same product

neutrinolabs: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-41252xrdp: lib_palette_update Heap Buffer Overflow & RCE
    39Monitor
  • CVE-2025-68670xrdp improperly checks bounds of domain string length, which leads to Stack-based Buffer Overflow
    39Monitor
  • CVE-2024-39917xrdp allows an ininite number of login attempts
    39Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2017-6967Mar 17, 2017 · xrdp 0.9.1 calls the PAM function auth_start_session() in an incorrect location, leading to PAM session modules not being properly initializ
    29Monitor
  • ← EarlierCVE-2017-16927Nov 23, 2017 · The scp_v0s_accept function in sesman/libscp/libscp_v0.c in the session manager in xrdp through 0.9.4 uses an untrusted integer as a write l
    33Monitor
  • Later →CVE-2022-23613Feb 7, 2022 · Privilege escalation on xrdp
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:xrdp0.9.12-1.1 · Debian:12Package registry (OSV)
opensuse:xrdp0.9.6-lp151.4.6.1 · openSUSE:Leap 15.1Package registry (OSV)
suse:xrdp0.9.10-3.3.1 · SUSE:Linux Enterprise Server 12 SP5Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-121 · Stack-based Buffer Overflow

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records