Protect yourself against future threats.
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2024.2259
ICS Advisory | ICSA-24-102-01 Siemens SIMATIC S7-1500
12 April 2024
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: Siemens SIMATIC S7-1500
Publisher: ICS-CERT
Operating System: Network Appliance
Resolution: Mitigation
CVE Names: CVE-2023-45898 CVE-2023-6931 CVE-2023-6817
CVE-2023-6932 CVE-2023-6121 CVE-2023-5678
CVE-2024-0727
Original Bulletin:
https://www.cisa.gov/news-events/ics-advisories/icsa-24-102-01
Comment: CVSS (Max): 7.8 CVE-2023-6932 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVSS Source: ICS-CERT
Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- --------------------------BEGIN INCLUDED TEXT--------------------
ICS Advisory (ICSA-24-102-01)
Siemens SIMATIC S7-1500
Release Date
April 11, 2024
As of January 10, 2023, CISA will no longer be updating ICS security advisories
for Siemens product vulnerabilities beyond the initial advisory. For the most
up-to-date information on vulnerabilities in this advisory, please see Siemens'
ProductCERT Security Advisories (CERT Services | Services | Siemens Global).
1. EXECUTIVE SUMMARY
o CVSS v3 7.8
o ATTENTION : Exploitable remotely/low attack complexity
o Vendor : Siemens
o Equipment : SIMATIC S7-1500
o Vulnerabilities : Improper Check for Unusual or Exceptional Conditions,
Improper Input Validation, Use After Free, Out-of-bounds Write
2. RISK EVALUATION
Successful exploitation of these vulnerabilities could allow an attack to cause
a heap-based buffer overflow, local privilege escalation, kernel information
leak, and a denial-of-service condition.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following Siemens products are affected:
o Siemens SIMATIC S7-1500 TM MFP (GNU/Linux subsystem): All versions
3.2 Vulnerability Overview
3.2.1 IMPROPER CHECK FOR UNUSUAL OR EXCEPTIONAL CONDITIONS CWE-754
Applications that use the functions DH_generate_key() to generate an X9.42 DH
key may experience long delays. Likewise, applications that use
DH_check_pub_key(), DH_check_pub_key_ex() or EVP_PKEY_public_check() to check
an X9.42 DH key or X9.42 DH parameters may experience long delays. Where the
key or parameters that are being checked have been obtained from an untrusted
source, this may lead to a denial-of-service condition. An application that
calls DH_generate_key() or DH_check_pub_key() and supplies a key or parameters
obtained from an untrusted source could be vulnerable to a denial-of-service
attack. DH_generate_key() and DH_check_pub_key() are also called by a number of
other OpenSSL functions. Also vulnerable are the OpenSSL pkey command line
application when using the "-pubcheck" option, as well as the OpenSSL genpkey
command line application. The OpenSSL SSL/TLS implementation is not affected by
this issue. The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this
issue.
CVE-2023-5678 has been assigned to this vulnerability. A CVSS v3 base score of
5.3 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N
/S:U/C:N/I:N/A:L ).
3.2.2 IMPROPER INPUT VALIDATION CWE-20
An out-of-bounds read vulnerability was found in the NVMe-oF/TCP subsystem in
the Linux kernel. This issue may allow a remote attacker to send a crafted TCP
packet, triggering a heap-based buffer overflow that results in kmalloc data
being printed and potentially leaked to the kernel ring buffer (dmesg).
CVE-2023-6121 has been assigned to this vulnerability. A CVSS v3 base score of
4.3 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:L/UI:N
/S:U/C:L/I:N/A:N ).
3.2.3 USE AFTER FREE CWE-416
A use-after-free vulnerability in the Linux kernel's netfilter: nf_tables
component can be exploited to achieve local privilege escalation. The function
nft_pipapo_walk did not skip inactive elements during set walk which could lead
double deactivations of PIPAPO (Pile Packet Policies) elements, leading to
use-after-free. We recommend upgrading past commit
317eb9685095678f2c9f5a8189de698c5354316a.
CVE-2023-6817 has been assigned to this vulnerability. A CVSS v3 base score of
7.8 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:L/AC:L/PR:L/UI:N
/S:U/C:H/I:H/A:H ).
3.2.4 OUT-OF-BOUNDS WRITE CWE-787
A heap out-of-bounds write vulnerability in the Linux kernel's Performance
Events system component can be exploited to achieve local privilege escalation.
A perf_event's read_size can overflow, leading to a heap out-of-bounds
increment or write in perf_read_group(). We recommend upgrading past commit
382c27f4ed28f803b1f1473ac2d8db0afc795a1b.
CVE-2023-6931 has been assigned to this vulnerability. A CVSS v3 base score of
7.8 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:L/AC:L/PR:L/UI:N
/S:U/C:H/I:H/A:H ).
3.2.5 USE AFTER FREE CWE-416
A use-after-free vulnerability in the Linux kernel's ipv4: igmp component can
be exploited to achieve local privilege escalation. A race condition can be
exploited to cause a timer to be mistakenly registered on a RCU read locked
object which is freed by another thread. We recommend upgrading past commit
e2b706c691905fe78468c361aaabc719d0a496f1.
CVE-2023-6932 has been assigned to this vulnerability. A CVSS v3 base score of
7.8 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:L/AC:L/PR:L/UI:N
/S:U/C:H/I:H/A:H ).
3.2.6 IMPROPER INPUT VALIDATION CWE-20
The Linux kernel before 6.5.4 has an es1 use-after-free in fs/ext4/
extents_status.c, related to ext4_es_insert_extent.
CVE-2023-45898 has been assigned to this vulnerability. A CVSS v3 base score of
7.8 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:L/AC:L/PR:L/UI:N
/S:U/C:H/I:H/A:H ).
3.2.7 USE AFTER FREE CWE-416
A use-after-free issue was found in igmp_start_timer in net/ipv4/igmp.c in the
network sub-component in the Linux Kernel. This flaw allows a local user to
observe a refcnt use-after-free issue when receiving an igmp query packet,
leading to a kernel information leak.
CVE-2023-6121 has been assigned to this vulnerability. A CVSS v3 base score of
5.5 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:L/AC:L/PR:L/UI:N
/S:U/C:H/I:N/A:N ).
3.2.8 IMPROPER INPUT VALIDATION CWE-20
Processing a maliciously formatted PKCS12 file may lead OpenSSL to crash
leading to a potential denial-of-service attack Impact summary: Applications
loading files in the PKCS12 format from untrusted sources might terminate
abruptly. A file in PKCS12 format can contain certificates and keys and may
come from an untrusted source. The PKCS12 specification allows certain fields
to be NULL, but OpenSSL does not correctly check for this case. This can lead
to a NULL pointer dereference that results in OpenSSL crashing. If an
application processes PKCS12 files from an untrusted source using the OpenSSL
APIs then that application will be vulnerable to this issue. OpenSSL APIs that
are vulnerable to this are: PKCS12_parse(), PKCS12_unpack_p7data(),
PKCS12_unpack_p7encdata(), PKCS12_unpack_authsafes() and PKCS12_newpass(). We
have also fixed a similar issue in SMIME_write_PKCS7(). However, since this
function is related to writing data, we do not consider it security
significant. The FIPS modules in 3.2, 3.1, and 3.0 are not affected by this
issue.
CVE-2024-0727 has been assigned to this vulnerability. A CVSS v3 base score of
5.5 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:L/AC:L/PR:N/UI:R
/S:U/C:N/I:N/A:H ).
3.3 BACKGROUND
o CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
o COUNTRIES/AREAS DEPLOYED: Worldwide
o COMPANY HEADQUARTERS LOCATION: Germany
3.4 RESEARCHER
Siemens reported these vulnerabilities to CISA.
4. MITIGATIONS
Siemens has identified the following specific workarounds and mitigations users
can apply to reduce risk:
o Only build and run applications from trusted sources.
As a general security measure, Siemens recommends protecting network access to
devices with appropriate mechanisms. To operate the devices in a protected IT
environment, Siemens recommends configuring the environment according to
Siemens' operational guidelines for industrial security and following
recommendations in the product manuals.
Additional information on industrial security by Siemens can be found on the
Siemens industrial security webpage .
For more information see the associated Siemens security advisory SSA-265688 in
HTML and CSAF .
CISA recommends users take defensive measures to minimize the risk of
exploitation of these vulnerabilities, such as:
o Minimize network exposure for all control system devices and/or systems,
ensuring they are not accessible from the internet .
o Locate control system networks and remote devices behind firewalls and
isolating them from business networks.
o When remote access is required, use more secure methods, such as Virtual
Private Networks (VPNs). Recognize VPNs may have vulnerabilities, should be
updated to the most recent version available, and are only as secure as the
connected devices.
CISA reminds organizations to perform proper impact analysis and risk
assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices
on the ICS webpage on cisa.gov . Several CISA products detailing cyber defense
best practices are available for reading and download, including Improving
Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies .
CISA encourages organizations to implement recommended cybersecurity strategies
for proactive defense of ICS assets .
Additional mitigation guidance and recommended practices are publicly available
on the ICS webpage at cisa.gov in the technical information paper,
ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation
Strategies .
Organizations observing suspected malicious activity should follow established
internal procedures and report findings to CISA for tracking and correlation
against other incidents.
CISA also recommends users take the following measures to protect themselves
from social engineering attacks:
o Do not click web links or open attachments in unsolicited email messages.
o Refer to Recognizing and Avoiding Email Scams for more information on
avoiding email scams.
o Refer to Avoiding Social Engineering and Phishing Attacks for more
information on social engineering attacks.
No known public exploitation specifically targeting these vulnerabilities has
been reported to CISA at this time.
5. UPDATE HISTORY
o April 11, 2024: Initial Publication
This product is provided subject to this Notification and this Privacy & Use
policy.
Vendor
Siemens
- --------------------------END INCLUDED TEXT----------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.
NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
https://www.auscert.org.au/bulletins/
===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
===========================================================================