7.4
HIGH
CVE-2020-27738
Siemens Nucleus DNS Pointer Offset Vulnerability
Description

A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions < V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions < V2.8.20), APOGEE PXC Modular (BACnet) (All versions < V3.5.5), APOGEE PXC Modular (P2 Ethernet) (All versions < V2.8.20), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.3), Nucleus ReadyStart V4 (All versions < V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0), TALON TC Compact (BACnet) (All versions < V3.5.5), TALON TC Modular (BACnet) (All versions < V3.5.5). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition.

INFO

Published Date :

April 22, 2021, 9:15 p.m.

Last Modified :

Aug. 8, 2023, 10:15 a.m.

Source :

[email protected]

Remotely Exploitable :

Yes !

Impact Score :

5.2

Exploitability Score :

2.2
Affected Products

The following products are affected by CVE-2020-27738 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Siemens nucleus_net
2 Siemens nucleus_readystart_v3
3 Siemens nucleus_readystart_v4
4 Siemens nucleus_source_code
5 Siemens simotics_connect_400_firmware
6 Siemens apogee_pxc_compact_\(p2_ethernet\)_firmware
7 Siemens apogee_pxc_modular_\(bacnet\)_firmware
8 Siemens apogee_pxc_modular_\(p2_ethernet\)_firmware
9 Siemens talon_tc_compact_\(bacnet\)_firmware
10 Siemens talon_tc_modular_\(bacnet\)_firmware
: Total Affected Vendor : 1 | Products : 10
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2020-27738.

URL Resource
https://cert-portal.siemens.com/productcert/pdf/ssa-180579.pdf
https://cert-portal.siemens.com/productcert/pdf/ssa-669158.pdf Patch Vendor Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-705111.pdf Patch Vendor Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2020-27738 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2020-27738 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Aug. 08, 2023

    Action Type Old Value New Value
    Changed Description A vulnerability has been identified in Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.3), Nucleus ReadyStart V4 (All versions < V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition. A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions < V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions < V2.8.20), APOGEE PXC Modular (BACnet) (All versions < V3.5.5), APOGEE PXC Modular (P2 Ethernet) (All versions < V2.8.20), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.3), Nucleus ReadyStart V4 (All versions < V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0), TALON TC Compact (BACnet) (All versions < V3.5.5), TALON TC Modular (BACnet) (All versions < V3.5.5). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition.
    Added CVSS V3.1 Siemens AG AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H
    Added Reference https://cert-portal.siemens.com/productcert/pdf/ssa-180579.pdf [No Types Assigned]
  • Modified Analysis by [email protected]

    Apr. 22, 2022

    Action Type Old Value New Value
    Changed CPE Configuration OR *cpe:2.3:a:siemens:capital_vstar:-:*:*:*:*:*:*:* *cpe:2.3:a:siemens:nucleus_4:*:*:*:*:*:*:*:* versions up to (excluding) 4.1.0 *cpe:2.3:a:siemens:nucleus_net:*:*:*:*:*:*:*:* *cpe:2.3:a:siemens:nucleus_readystart:*:*:*:*:*:*:*:* versions up to (excluding) 2017.02.3 *cpe:2.3:a:siemens:nucleus_source_code:-:*:*:*:*:*:*:* OR *cpe:2.3:a:siemens:nucleus_net:*:*:*:*:*:*:*:* *cpe:2.3:a:siemens:nucleus_readystart_v3:*:*:*:*:*:*:*:* versions up to (excluding) 2017.02.3 *cpe:2.3:a:siemens:nucleus_readystart_v4:*:*:*:*:*:*:*:* versions up to (excluding) 4.1.0 *cpe:2.3:a:siemens:nucleus_source_code:-:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Jan. 11, 2022

    Action Type Old Value New Value
    Changed Description A vulnerability has been identified in Capital VSTAR (Versions including affected DNS modules), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.3), Nucleus ReadyStart V4 (All versions < V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition. A vulnerability has been identified in Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.3), Nucleus ReadyStart V4 (All versions < V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition.
  • CVE Modified by [email protected]

    Nov. 17, 2021

    Action Type Old Value New Value
    Changed Description A vulnerability has been identified in Nucleus 4 (All versions < V4.1.0), Nucleus NET (All versions), Nucleus RTOS (versions including affected DNS modules), Nucleus ReadyStart (All versions < V2017.02.3), Nucleus Source Code (versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0), VSTAR (versions including affected DNS modules). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition. A vulnerability has been identified in Capital VSTAR (Versions including affected DNS modules), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.3), Nucleus ReadyStart V4 (All versions < V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition.
  • Modified Analysis by [email protected]

    Nov. 12, 2021

    Action Type Old Value New Value
    Removed CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:N/A:P)
    Added CVSS V2 NIST (AV:N/AC:M/Au:N/C:P/I:N/A:P)
    Removed CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
    Added CVSS V3.1 NIST AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
    Removed CPE Configuration OR *cpe:2.3:a:siemens:nucleus_4:*:*:*:*:*:*:*:* versions up to (excluding) 4.1.0 *cpe:2.3:a:siemens:nucleus_net:*:*:*:*:*:*:*:* *cpe:2.3:a:siemens:nucleus_readystart:*:*:*:*:*:*:*:* versions up to (excluding) 2017.02.3 *cpe:2.3:a:siemens:nucleus_source_code:-:*:*:*:*:*:*:* *cpe:2.3:a:siemens:vstar:-:*:*:*:*:*:*:* *cpe:2.3:o:siemens:nucleus_rtos:-:*:*:*:*:*:*:*
    Added CPE Configuration OR *cpe:2.3:a:siemens:capital_vstar:-:*:*:*:*:*:*:* *cpe:2.3:a:siemens:nucleus_4:*:*:*:*:*:*:*:* versions up to (excluding) 4.1.0 *cpe:2.3:a:siemens:nucleus_net:*:*:*:*:*:*:*:* *cpe:2.3:a:siemens:nucleus_readystart:*:*:*:*:*:*:*:* versions up to (excluding) 2017.02.3 *cpe:2.3:a:siemens:nucleus_source_code:-:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Nov. 10, 2021

    Action Type Old Value New Value
    Changed Description A vulnerability has been identified in Capital VSTAR (Versions including affected DNS modules), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.3), Nucleus ReadyStart V4 (All versions < V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition. A vulnerability has been identified in Nucleus 4 (All versions < V4.1.0), Nucleus NET (All versions), Nucleus RTOS (versions including affected DNS modules), Nucleus ReadyStart (All versions < V2017.02.3), Nucleus Source Code (versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0), VSTAR (versions including affected DNS modules). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition.
  • CVE Modified by [email protected]

    Nov. 09, 2021

    Action Type Old Value New Value
    Changed Description A vulnerability has been identified in Nucleus 4 (All versions < V4.1.0), Nucleus NET (All versions), Nucleus RTOS (versions including affected DNS modules), Nucleus ReadyStart (All versions < V2017.02.3), Nucleus Source Code (versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0), VSTAR (versions including affected DNS modules). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition. A vulnerability has been identified in Capital VSTAR (Versions including affected DNS modules), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.3), Nucleus ReadyStart V4 (All versions < V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition.
  • Initial Analysis by [email protected]

    Apr. 30, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:N/A:P)
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
    Changed Reference Type https://cert-portal.siemens.com/productcert/pdf/ssa-669158.pdf No Types Assigned https://cert-portal.siemens.com/productcert/pdf/ssa-669158.pdf Patch, Vendor Advisory
    Changed Reference Type https://cert-portal.siemens.com/productcert/pdf/ssa-705111.pdf No Types Assigned https://cert-portal.siemens.com/productcert/pdf/ssa-705111.pdf Patch, Vendor Advisory
    Added CWE NIST CWE-119
    Added CPE Configuration OR *cpe:2.3:a:siemens:nucleus_4:*:*:*:*:*:*:*:* versions up to (excluding) 4.1.0 *cpe:2.3:a:siemens:nucleus_net:*:*:*:*:*:*:*:* *cpe:2.3:a:siemens:nucleus_readystart:*:*:*:*:*:*:*:* versions up to (excluding) 2017.02.3 *cpe:2.3:a:siemens:nucleus_source_code:-:*:*:*:*:*:*:* *cpe:2.3:a:siemens:vstar:-:*:*:*:*:*:*:* *cpe:2.3:o:siemens:nucleus_rtos:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:siemens:simotics_connect_400_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 0.5.0.0 OR cpe:2.3:h:siemens:simotics_connect_400:-:*:*:*:*:*:*:*
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2020-27738 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2020-27738 weaknesses.

CAPEC-8: Buffer Overflow in an API Call Buffer Overflow in an API Call CAPEC-9: Buffer Overflow in Local Command-Line Utilities Buffer Overflow in Local Command-Line Utilities CAPEC-10: Buffer Overflow via Environment Variables Buffer Overflow via Environment Variables CAPEC-14: Client-side Injection-induced Buffer Overflow Client-side Injection-induced Buffer Overflow CAPEC-24: Filter Failure through Buffer Overflow Filter Failure through Buffer Overflow CAPEC-42: MIME Conversion MIME Conversion CAPEC-44: Overflow Binary Resource File Overflow Binary Resource File CAPEC-45: Buffer Overflow via Symbolic Links Buffer Overflow via Symbolic Links CAPEC-46: Overflow Variables and Tags Overflow Variables and Tags CAPEC-47: Buffer Overflow via Parameter Expansion Buffer Overflow via Parameter Expansion CAPEC-100: Overflow Buffers Overflow Buffers CAPEC-123: Buffer Manipulation Buffer Manipulation
Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.41 }} -0.10%

score

0.71143

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
: