7.5 High
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
9.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.5 High
AI Score
Confidence
High
0.937 High
EPSS
Percentile
99.1%
This updated advisory is a follow-up to the original advisory titled ICSA-19-211-01 Wind River VxWorks that was published July 30, 2019, on the ICS webpage on us-cert.gov.
Successful exploitation of these vulnerabilities could allow remote code execution.
Wind River reports the following versions of VxWorks are affected:
The following VxWorks products are not affected:
This vulnerability resides in the IPv4 option parsing and may be triggered by IPv4 packets containing invalid options.
The most likely outcome of triggering this defect is that the tNet0 task crashes. This vulnerability can result in remote code execution.
CVE-2019-12256 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
DHCP packets may go past the local area network (LAN) via DHCP-relays, but are otherwise confined to the LAN.
The DHCP-client may be used by VxWorks and in the bootrom. Bootrom, using DHCP/BOOTP, is only vulnerable during the boot-process.
This vulnerability may be used to overwrite the heap, which could result in a later crash when a task requests memory from the heap. This vulnerability can result in remote code execution.
CVE-2019-12257 has been assigned to this vulnerability. A CVSS v3 base score of 8.8 has been calculated; the CVSS vector string is (AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
An attacker can either hijack an existing TCP-session and inject bad TCP-segments or establish a new TCP-session on any TCP-port listened to by the target.
This vulnerability could lead to a buffer overflow of up to a full TCP receive-window (by default, 10k-64k depending on version). The buffer overflow occurs in the task calling recv()/recvfrom()/recvmsg().
Applications that pass a buffer equal to or larger than a full TCP-window are not susceptible to this attack. Applications passing a stack-allocated variable as a buffer are the easiest to exploit.
The most likely outcome is a crash of the application reading from the affected socket, which could result in remote code execution.
CVE-2019-12255 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
This vulnerability could lead to a buffer overflow of up to a full TCP receive-window (by default, 10k-64k depending on version). The buffer overflow happens in the task calling recv()/recvfrom()/recvmsg().
Applications that pass a buffer equal to or larger than a full TCP-window are not susceptible to this attack. Applications passing a stack-allocated variable as a buffer are the easiest to exploit.
The most likely outcome is a crash of the application reading from the affected socket, which could result in remote code execution.
CVE-2019-12260 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
The impact of this vulnerability is a buffer overflow of up to a full TCP receive-window (by default, 10k-64k depending on version). The buffer overflow happens in the task calling recv()/recvfrom()/recvmsg().
Applications that pass a buffer equal to or larger than a full TCP-window are not susceptible to this attack. Applications passing a stack-allocated variable as a buffer are the easiest to exploit.
The most likely outcome is a crash of the application reading from the affected socket, which could result in remote code execution.
CVE-2019-12261 has been assigned to this vulnerability. A CVSS v3 base score of 8.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).
This vulnerability relies on a race-condition between the network task (tNet0) and the receiving application. It is very difficult to trigger the race on a system with a single CPU-thread enabled, and there is no way to reliably trigger a race on SMP targets.
CVE-2019-12263 has been assigned to this vulnerability. A CVSS v3 base score of 8.1 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H).
An attacker with the source and destination TCP-port and IP-addresses of a session can inject invalid TCP-segments into the flow, causing the TCP-session to be reset.
An application will see this as an ECONNRESET error message when using the socket after such an attack.
The most likely outcome is a crash of the application reading from the affected socket.
CVE-2019-12258 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
This vulnerability requires that at least one IPv4 multicast address has been assigned to the target in an incorrect way (e.g., using the API intended for assigning unicast-addresses).
An attacker may use CVE-2019-12264 to incorrectly assign a multicast IP-address.
An attacker on the same LAN as the target system may use this vulnerability to cause a NULL-pointer dereference, which most likely will crash the tNet0 task.
CVE-2019-12259 has been assigned to this vulnerability. A CVSS v3 base score of 6.3 has been calculated; the CVSS vector string is (AV:A/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H).
An attacker residing on the LAN can send reverse-ARP responses to the victim system to assign unicast IPv4 addresses to the target.
CVE-2019-12262 has been assigned to this vulnerability. A CVSS v3 base score of 7.1 has been calculated; the CVSS vector string is (AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H).
An attacker residing on the LAN may choose to hijack a DHCP-client session that requests an IPv4 address. The attacker can send a multicast IP-address in the DHCP offer/ack message, which the victim system then incorrectly assigns.
This vulnerability can be combined with CVE-2019-12259 to create a denial-of-service condition.
CVE-2019-12264 has been assigned to this vulnerability. A CVSS v3 base score of 7.1 has been calculated; the CVSS vector string is (AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H).
The IGMPv3 reception handler does not expect packets to be spread across multiple IP-fragments.
CVE-2019-12265 has been assigned to this vulnerability. A CVSS v3 base score of 5.4 has been calculated; the CVSS vector string is (AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L).
Wind River, working with Armis researchers Gregory Vishnepolsky, Dor Zusman, and Ben Seri, reported these vulnerabilities to CISA.
Wind River has produced controls and patches to mitigate the reported vulnerabilities. To obtain patches, email [email protected] and indicate the VxWorks major version for which you need source patches.
For more detailed information on the vulnerabilities and the mitigating controls, please see the Wind River advisory at: <https://www.windriver.com/security/announcements/tcp-ip-network-stack-ipnet-urgent11/>
Additional vendors affected by the reported vulnerabilities have also released security advisories related to their affected products. Those advisories are as follows:
Rockwell Automation (login required) - <https://rockwellautomation.custhelp.com/app/answers/detail/a_id/1088561>
--------- Begin Update A Part 1 of 1 ---------
DrΓ€ger β <https://static.draeger.com/security>
Schneider Electric β <https://www.se.com/ww/en/download/document/SESB-2019-214-01/>
--------- End Update A Part 1 of 1 ---------
CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:
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 us-cert.gov. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
Additional mitigation guidance and recommended practices are publicly available on the ICS webpage on us-cert.gov in the Technical Information Paper, ICS-TIP-12-146-01BβTargeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to CISA for tracking and correlation against other incidents.
No known public exploits specifically target these vulnerabilities.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-12255
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-12256
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-12257
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-12258
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-12259
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-12260
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-12261
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-12262
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-12263
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-12264
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-12264
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-12265
cwe.mitre.org/data/definitions/119.html
cwe.mitre.org/data/definitions/119.html
cwe.mitre.org/data/definitions/121.html
cwe.mitre.org/data/definitions/122.html
cwe.mitre.org/data/definitions/191.html
cwe.mitre.org/data/definitions/362.html
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cwe.mitre.org/data/definitions/88.html
cwe.mitre.org/data/definitions/88.html
cwe.mitre.org/data/definitions/88.html
cwe.mitre.org/data/definitions/88.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
rockwellautomation.custhelp.com/app/answers/detail/a_id/1088561
security.business.xerox.com/en-us/news/wind-river-vxworks-ipnet-tcp-ip-stack-vulnerabilities/
static.draeger.com/security
twitter.com/CISAgov
twitter.com/intent/tweet?text=Wind%20River%20VxWorks%20%28Update%20A%29+https://www.cisa.gov/news-events/ics-advisories/icsa-19-211-01
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www.us-cert.gov/ics
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www.us-cert.gov/ics/alerts/ICS-ALERT-10-301-01
www.us-cert.gov/ics/recommended-practices
www.us-cert.gov/ics/tips/ICS-TIP-12-146-01B
www.us-cert.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf
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mailto:?subject=Wind%20River%20VxWorks%20%28Update%20A%29&body=www.cisa.gov/news-events/ics-advisories/icsa-19-211-01
7.5 High
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
9.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.5 High
AI Score
Confidence
High
0.937 High
EPSS
Percentile
99.1%