xrdp up to 0.9.4 Session Manager libscp_v0.c scp_v0s_accept input validation

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.5$0-$5k0.00

A vulnerability, which was classified as critical, was found in xrdp up to 0.9.4. Affected is the function scp_v0s_accept in the library sesman/libscp/libscp_v0.c of the component Session Manager. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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 length, which allows local users to cause a denial of service (buffer overflow and application crash) or possibly have unspecified other impact via a crafted input stream.

The bug was discovered 11/28/2017. The weakness was released 11/23/2017 (GitHub Repository). The advisory is shared for download at github.com. This vulnerability is traded as CVE-2017-16927 since 11/23/2017. The attack needs to be approached locally. The successful exploitation requires a authentication. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 105126 (Fedora 25 : 1:xrdp (2017-1fb805bfc2)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 277082 (Fedora Security Update for xrdp (FEDORA-2017-1c73749b66)).

Upgrading eliminates this vulnerability. A possible mitigation has been published 3 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (105126).

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.8
VulDB Meta Temp Score: 6.5

VulDB Base Score: 5.3
VulDB Temp Score: 4.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.4
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
unlockunlockunlockunlockunlockunlock
unlockunlockunlockunlockunlockunlock
unlockunlockunlockunlockunlockunlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Dayunlockunlockunlockunlock
Todayunlockunlockunlockunlock

Nessus ID: 105126
Nessus Name: Fedora 25 : 1:xrdp (2017-1fb805bfc2)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 902297
OpenVAS Name: Fedora Update for xrdp FEDORA-2017-1fb805bfc2
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Patch: github.com

Timelineinfo

11/23/2017 🔍
11/23/2017 +0 days 🔍
11/23/2017 +0 days 🔍
11/24/2017 +1 days 🔍
11/28/2017 +4 days 🔍
12/09/2017 +11 days 🔍
12/11/2017 +2 days 🔍
01/16/2023 +1862 days 🔍

Sourcesinfo

Advisory: FEDORA-2017-1fb805bfc2
Status: Not defined
Confirmation: 🔍

CVE: CVE-2017-16927 (🔍)

Entryinfo

Created: 11/24/2017 08:07 AM
Updated: 01/16/2023 10:08 AM
Changes: 11/24/2017 08:07 AM (72), 12/10/2019 03:35 PM (4), 01/16/2023 10:04 AM (5), 01/16/2023 10:08 AM (1)
Complete: 🔍
Cache ID: 18:1D2:40

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Want to stay up to date on a daily basis?

Enable the mail alert feature now!