CERT-SEI

Microsoft has released Security Advisory ADV200001,which describes a memory corruption vulnerability in the Scripting Engine. This vulnerability is being exploited in the wild.

CDNs use HTTP caching software to provide high availability and high performance by distributing the service spatially relative to end-users. The HTTP caching software interprets the HTTP request from a website visitor(web client)using the supplied HTTP headers to select and deliver appropriate content. The content can either be delivered from the local cache or collected by reaching the appropriate back end web servers. This vulnerability works by sending arbitrary headers into the HTTP request stream,which may be processed by the back end web server or by the HTTP caching software. If either the web server or the HTTP caching software is vulnerable,it will include the attackers injected content in the response without performing any type of sanitization. Once the attacker's malicious content is returned,it will also be cached by the HTTP caching software. The HTTP caching software will continue to serve the malicious content to all future visitors of the website until the cache expires or is deleted. This allows the attacker to inject arbitrary content once and have multiple future visitors of the CDN hosted website collect the attacker's content and execute unwanted scripts. HTTP header injection using traditional headers,like the Host header and X-Forwarded-Host header,is not a new attack method. New HTTP headers like X-Forwarded-Proto,Referer,Upgrade-Insecure-Requests,and X-DNS-Prefetch-Control have been created to provide more capabilities for HTTP processing. Cloud caching in addition to newly available headers allows for an increase in prolonged,large scale attacks against busy and popular websites. Some examples of the vulnerable headers are: Content-Security-Policy-Report-Only Forwarded Server-Timing Set-Cookie Strict-Transport-Security X-Forwarded-Proto Location Accept-Language Cookie X-Forwarded-For X-Forwarded-Host Referer Max-Forwards There are at least two common reasons why these attacks are possible: 1. Certain HTTP headers(e.g.,X-Forwarded-Host)are sent by the reverse proxy or CDN to the web server and are many times presumed to be generated/modified by the CDN and therefore trusted. 2. Certain HTTP headers(e.g.,User-Agent)are not sanitized by the CDN before being delivered to the web server.

Microsoft Windows Remote Desktop Gateway(RD Gateway)is a Windows Server component that provides access to Remote Desktop services without requiring the client system to be present on the same network as the target system. Originally launched as Terminal Services Gateway(TS Gateway)with Windows Server 2008,RD Gateway is a recommended way to provide Remote Desktop connectivity to cloud-based systems. For example,guidance has been provided for using RD Gateway with AWS,and also with Azure. The use of RD Gateway is recommended to reduce the attack surface of Windows-based hosts. Microsoft RD Gateway contains two vulnerabilities that can allow an unauthenticated remote attacker to execute arbitrary code with SYSTEM privileges.

The Microsoft Windows CryptoAPI,which is provided by Crypt32.dll,fails to validate ECC certificates in a way that properly leverages the protections that ECC cryptography should provide. As a result,an attacker may be able to craft a certificate that appears to have the ability to be traced to a trusted root certificate authority. Any software,including third-party non-Microsoft software,that relies on the Windows CertGetCertificateChain()function to determine if an X.509 certificate can be traced to a trusted root CA may incorrectly determine the trustworthiness of a certificate chain.

Citrix has published a security bulletin that mentions a vulnerability that can be exploited to achieve arbitrary code execution by a remote,unauthenticated attacker. Although the bulletin does not describe details about the vulnerability,the mitigation steps describe techniques to block the handling of requests that contain a directory traversal attempt(/../)and also requests that attempt to access the/vpns/directory. Although this vulnerability was disclosed by Citrix on December 17,2019,Citrix has not yet provided a software update to address the issue.

A vulnerability in the Boot ROM of some Apple devices can be exploited by an unauthenticated local attacker to execute arbitrary code upon booting those devices. The Boot ROM,which is located within the processor,contains the first code executed by the processor upon booting the device. Because the Boot ROM is read-only,it cannot be patched with a firmware update. Apple devices that implement processing chips A5 through A11 are vulnerable. This corresponds to iPhone models 4S through X; additionally,certain models of iPad,Apple Watch,iPod Touch,and Apple TV are vulnerable. See the Malwarebytes blog entry for a full list of affected devices. Further details about the vulnerability are available in Ars Technica's interview with the vulnerability's discoverer.

Telos AMHS is a web-based messaging system that supports DoD and Intelligence Community(IC)security marking requirements. AMHS versions prior to version 4.1.5.5 contain multiple XSS vulnerabilities and also fail to properly restrict access to information about other users on the system.

The Security Considerations section of RFC7540 discusses some of the considerations needed for HTTP/2 connections as they demand more resources to operate than HTTP/1.1 connections. While it generally covers expected behavior considerations,how to mitigate abnormal behavior is left to the implementer which can leave it open to the following weaknesses. CVE-2019-9511,also known as Data Dribble The attacker requests a large amount of data from a specified resource over multiple streams. They manipulate window size and stream priority to force the server to queue the data in 1-byte chunks. Depending on how efficiently this data is queued,this can consume excess CPU,memory,or both,potentially leading to a denial of service. CVE-2019-9512,also known as Ping Flood The attacker sends continual pings to an HTTP/2 peer,causing the peer to build an internal queue of responses. Depending on how efficiently this data is queued,this can consume excess CPU,memory,or both,potentially leading to a denial of service. CVE-2019-9513,also known as Resource Loop The attacker creates multiple request streams and continually shuffles the priority of the streams in a way that causes substantial churn to the priority tree. This can consume excess CPU,potentially leading to a denial of service. CVE-2019-9514,also known as Reset Flood The attacker opens a number of streams and sends an invalid request over each stream that should solicit a stream of RST_STREAM frames from the peer. Depending on how the peer queues the RST_STREAM frames,this can consume excess memory,CPU,or both,potentially leading to a denial of service. CVE-2019-9515,also known as Settings Flood The attacker sends a stream of SETTINGS frames to the peer. Since the RFC requires that the peer reply with one acknowledgement per SETTINGS frame,an empty SETTINGS frame is almost equivalent in behavior to a ping. Depending on how efficiently this data is queued,this can consume excess CPU,memory,or both,potentially leading to a denial of service. CVE-2019-9516,also known as 0-Length Headers Leak The attacker sends a stream of headers with a 0-length header name and 0-length header value,optionally Huffman encoded into 1-byte or greater headers. Some implementations allocate memory for these headers and keep the allocation alive until the session dies. This can consume excess memory,potentially leading to a denial of service. CVE-2019-9517,also known as Internal Data Buffering The attacker opens the HTTP/2 window so the peer can send without constraint; however,they leave the TCP window closed so the peer cannot actually write(many of)the bytes on the wire. The attacker then sends a stream of requests for a large response object. Depending on how the servers queue the responses,this can consume excess memory,CPU,or both,potentially leading to a denial of service. CVE-2019-9518,also known as Empty Frame Flooding The attacker sends a stream of frames with an empty payload and without the end-of-stream flag. These frames can be DATA,HEADERS,CONTINUATION and/or PUSH_PROMISE. The peer spends time processing each frame disproportionate to attack bandwidth. This can consume excess CPU,potentially leading to a denial of service.

XLM macros Up to and including Microsoft Excel 4.0,a macro format called XLM was available. XLM macros predate the VBA macros that are more common with modern Microsoft Office systems,however current Microsoft Office versions still support XLM macros. SYLK and XLM macros XLM macros can be incorporated into SYLK files,as outlined by Outflank. Macros in the SYLK format are problematic in that Microsoft Office does not open in Protected View to help protect users. This means that users may be a single click away from arbitrary code execution via a document that originated from the internet. SYLK and XLM macros with Microsoft Office for Mac It has been reported that Office 2011 for Mac fails to warn users before opening SYLK files that contain XLM macros. According to this post,Microsoft has reported that Office 2016 and Office 2019 for Mac properly prompt the user before executing XLM macros in SYLK files. The Problem If Office for the Mac has been configured to use the"Disable all macros without notification"feature,XLM macros in SYLK files are executed without prompting the user. We have confirmed this behavior with fully-patched Office 2016 and Office 2019 for Mac systems.

Several D-Link routers contain CGI capability that is exposed to users as/apply_sec.cgi,and dispatched on the device by the binary/www/cgi/ssi. This CGI code contains two flaws: The/apply_sec.cgi code is exposed to unauthenticated users. The ping_ipaddr argument of the ping_test action fails to properly handle newline characters. Any arguments after a newline character sent as ping_ipaddr in a POST to/apply_sec.cgi are executed on the device with root privileges. The following devices are reported to be vulnerable: DIR-655 DIR-866L DIR-652 DHP-1565 DIR-855L DAP-1533 DIR-862L DIR-615 DIR-835 DIR-825

Pulse Secure released an out-of-cycle advisory along with software patches for the various affected products on April 24,2019. This addressed a number of vulnerabilities including a Remote Code Execution(RCE)vulnerability with pre-authentication access. This vulnerability has no viable workarounds except for applying the patches provided by the vendor and performing required system updates. The CVE-2019-11510 has a CVSS score of 10. The CVEs listed in the advisory are: CVE-2019-11510 - Unauthenticated remote attacker with network access via HTTPS can send a specially crafted URI to perform an arbitrary file reading vulnerability. CVE-2019-11509 - Authenticated attacker via the admin web interface can exploit this issue to execute arbitrary code on the Pulse Secure appliance. CVE-2019-11508 - A vulnerability in the Network File Share(NFS)of Pulse Connect Secure allows an authenticated end-user attacker to upload a malicious file to write arbitrary files to the local system. CVE-2019-11507 - A XSS issue has been found in Pulse Secure Application Launcher page. Pulse Connect Secure(PCS)8.3.x before 8.3R7.1,and 9.0.x before 9.0R3. CVE-2019-11543 - A XSS issue found the admin web console. Pulse Secure Pulse Connect Secure(PCS)9.0RX before 9.0R3.4,8.3RX before 8.3R7.1,and 8.1RX before 8.1R15.1 and Pulse Policy Secure 9.0RX before 9.0R3.2,5.4RX before 5.4R7.1,and 5.2RX before 5.2R12.1. CVE-2019-11542 - Authenticated attacker via the admin web interface can send a specially crafted message resulting in a stack buffer overflow. CVE-2019-11541 - Users using SAML authentication with Reuse Existing NC(Pulse)Session option may see authentication leaks CVE-2019-11540 - A vulnerability in the Pulse Secure could allow an unauthenticated,remote attacker to conduct a(end user)session hijacking attack. CVE-2019-11539 - Authenticated attacker via the admin web interface allow attacker to inject and execute command injection CVE-2019-11538 - A vulnerability in the Network File Share(NFS)of Pulse Connect Secure could allow an authenticated end-user attacker to access the contents of arbitrary files on the local file system. Exploitation of these vulnerabilities was demonstrated at various events and proved to be highly impactful due to the direct access to admin privileges and the consequent ability to infect multiple VPN connected users and their desktops. Initially there was a lack of clarity about CVE-2019-11510,as to whether it can be mitigated with the requirement of a client-certificate to prevent this attack. CERT/CC has confirmed with the vendor that this vulnerability cannot be mitigated using client certificate and furthermore there is no viable alternative to updating the Pulse Secure VPN software to a non-vulnerable version. Even if client certificates are required for user authentication,CVE-2019-11510 can be exploited by an unauthenticated remote attacker to obtain session IDs of active users stored in/data/runtime/mtmp/lmdb/randomVal/data.mdb. The attacker can use these session IDs to impersonate as one of the active users. If a Pulse Secure administrator is currently active and the administrative access is available to the attacker,attacker could gain administrative access to Pulse Secure VPN. It is highly recommended that all Pulse Secure VPN administrators perform the required upgrade on all their affected products. If your Pulse Secure VPN has been identified as End of Engineering(EOE)and End of Life(EOL),we highly recommend replacement of the VPN appliance entirely without any delay - please check Pulse Secure advisory for this information. Timelines of specific events: March 22,2019–Security researcher O. Tsai and M. Chang responsibly disclose vulnerability to Pulse Secure April 24,2019 - Initial advisory posted and software updates posted by Pulse Secure to the Download Center. April 25,2019–Assignment of CVE-2019-11510,CVE-2019-11509,CVE-2019-11508,CVE-2019-11507,CVE-2019-11543,CVE-2019-11542,CVE-2019-11541,CVE-2019-11540,CVE-2019-11539,CVE-2019-11538. April 26,2019 - Workaround provided for CVE-2019-11508 about disabling file sharing as a mitigation. May 28 2019–Large commercial vendors get reports of vulnerable VPN through Hacker One. July 31 2019–Full RCE use of exploit demonstrated using the admin session hash to get complete shell August 8 2019 - Meh Chang and Orange Tsai demonstrate the VPN issues across multiple vendors(Pulse Secure)with detailed attack on active VPN exploitation. August 24,2019–Bad Packets identifies over 14,500 vulnerable VPN servers globally still unpatched and in need of an upgrade October 7,2019–NSA produces a Cybersecurity Advisory on Pulse Secure and other VPN products being targeted actively by Advanced Persistent Threat actors

iTerm2 is a popular terminal emulator for macOS that supports terminal multiplexing using tmux integration and is frequently used by developers and system administrators. A vulnerability,identified as CVE-2019-9535,exists in the way that iTerm2 integrates with tmux's control mode,which may allow an attacker to execute arbitrary commands by providing malicious output to the terminal. This affects versions of iTerm2 up to and including 3.3.5.

The Cobham EXPLORER 710 is a portable satellite terminal used to provide satellite telecommunications and internet access. For consistency,“device” mentioned in the following section is defined as the Cobham EXPLORER 710. The affected firmware version is 1.07 for all of the vulnerabilities listed below unless otherwise noted. CVE-2019-9529 The web application portal has no authentication by default. This could allow an unauthenticated,local attacker connected to the device to access the portal and to make any change to the device. CVE-2019-9530 The web root directory has no access restrictions on downloading and reading all files. This could allow an unauthenticated,local attacker connected to the device to access and download any file found in the web root directory. CVE-2019-9531 The web application portal allows unauthenticated access to port 5454 on the device. This could allow an unauthenticated,remote attacker to connect to this port via Telnet and execute 86 Attention(AT)commands,including some that provide unauthenticated,shell-like access to the device. CVE-2019-9532 The web application portal sends the login password in cleartext. This could allow an unauthenticated,local attacker to intercept the password and gain access to the portal. CVE-2019-9533 The root password for the device is the same for all versions of firmware up to and including v1.08. This could allow an attacker to reverse-engineer the password from available versions to gain authenticated access to the device. CVE-2019-9534 The device does not validate its firmware image. Development scripts left in the firmware can be used to upload a custom firmware image that the device runs. This could allow an unauthenticated,local attacker to upload their own firmware that could be used to intercept or modify traffic,spoof or intercept GPS traffic,exfiltrate private data,hide a backdoor,or cause a denial-of-service. In addition to the findings above,we have found some configuration issues within the device that can leave it vulnerable to attackers. The default WiFi password is publicly documented as the serial number of the device and can be easily brute forced. Additionally,important security headers are missing,which leaves the device vulnerable to cross-site scripting and clickjacking.