HTTP/2 Rapid reset attack The HTTP/2 protocol allows clients to indicate to the server that a previous stream should be canceled by sending a RSTSTREAM frame. The protocol does not require the client and server to coordinate the cancellation in any way, the client may do it unilaterally. The client may also assume that the cancellation will take effect immediately when the server receives the RSTSTREAM frame, before any other data from that TCP connection is processed.

Abuse of this feature is called a Rapid Reset attack because it relies on the ability for an endpoint to send a RSTSTREAM frame immediately after sending a request frame, which makes the other endpoint start working and then rapidly resets the request. The request is canceled, but leaves the HTTP/2 connection open.

The HTTP/2 Rapid Reset attack built on this capability is simple: The client opens a large number of streams at once as in the standard HTTP/2 attack, but rather than waiting for a response to each request stream from the server or proxy, the client cancels each request immediately.

The ability to reset streams immediately allows each connection to have an indefinite number of requests in flight. By explicitly canceling the requests, the attacker never exceeds the limit on the number of concurrent open streams. The number of in-flight requests is no longer dependent on the round-trip time (RTT), but only on the available network bandwidth.

In a typical HTTP/2 server implementation, the server will still have to do significant amounts of work for canceled requests, such as allocating new stream data structures, parsing the query and doing header decompression, and mapping the URL to a resource. For reverse proxy implementations, the request may be proxied to the backend server before the RSTSTREAM frame is processed. The client on the other hand paid almost no costs for sending the requests. This creates an exploitable cost asymmetry between the server and the client.

Multiple software artifacts implementing HTTP/2 are affected. This advisory was originally ingested from the swift-nio-http2 repo advisory and their original conent follows.

swift-nio-http2 specific advisory swift-nio-http2 is vulnerable to a denial-of-service vulnerability in which a malicious client can create and then reset a large number of HTTP/2 streams in a short period of time. This causes swift-nio-http2 to commit to a large amount of expensive work which it then throws away, including creating entirely new Channels to serve the traffic. This can easily overwhelm an EventLoop and prevent it from making forward progress.

swift-nio-http2 1.28 contains a remediation for this issue that applies reset counter using a sliding window. This constrains the number of stream resets that may occur in a given window of time. Clients violating this limit will have their connections torn down. This allows clients to continue to cancel streams for legitimate reasons, while constraining malicious actors.

A stack-based buffer overflow in Fortinet FortiOS version 7.4.0 through 7.4.1 and 7.2.0 through 7.2.7 and 7.0.0 through 7.0.12 and 6.4.6 through 6.4.15 and 6.2.9 through 6.2.16 and 6.0.13 through 6.0.18 allows attacker to execute unauthorized code or commands via specially crafted CLI commands.

A heap-based buffer overflow vulnerability [CWE-122] in FortiOS, FortiManager, FortiAnalyzer, FortiManager Cloud, FortiAnalyzer Cloud, FortiProxy fgfmd daemon may allow an authenticated attacker to execute arbitrary code or commands via specifically crafted requests.

A insertion of sensitive information into sent data vulnerability in Fortinet FortiMail 7.4.0 through 7.4.2, FortiMail 7.2.0 through 7.2.6, FortiMail 7.0 all versions, FortiManager 7.6.0 through 7.6.1, FortiManager 7.4.1 through 7.4.3, FortiManager Cloud 7.4.1 through 7.4.3, FortiNDR 7.6.0 through 7.6.1, FortiNDR 7.4.0 through 7.4.8, FortiNDR 7.2 all versions, FortiNDR 7.1 all versions, FortiNDR 7.0 all versions, FortiNDR 1.5 all versions, FortiOS 7.6.0, FortiOS 7.4.0 through 7.4.4, FortiOS 7.2.0 through 7.2.8, FortiOS 7.0.0 through 7.0.15, FortiOS 6.4.0 through 6.4.15, FortiOS 6.2 all versions, FortiOS 6.0 all versions, FortiPAM 1.3 all versions, FortiPAM 1.2 all versions, FortiPAM 1.1 all versions, FortiPAM 1.0 all versions, FortiProxy 7.4.0 through 7.4.4, FortiProxy 7.2.0 through 7.2.10, FortiProxy 7.0 all versions, FortiProxy 2.0 all versions, FortiProxy 01.02 all versions, FortiProxy 1.2 all versions, FortiProxy 01.01 all versions, FortiProxy 1.1 all versions, FortiProxy 01.00 all versions, FortiRecorder 7.2.0 through 7.2.1, FortiRecorder 7.0.0 through 7.0.4, FortiTester 7.4.0 through 7.4.2, FortiTester 7.3 all versions, FortiTester 7.2 all versions, FortiTester 7.1 all versions, FortiTester 7.0 all versions, FortiTester 4.2 all versions, FortiVoice 7.0.0 through 7.0.4, FortiVoice 6.4.0 through 6.4.9, FortiVoice 6.0.7 through 6.0.12, FortiWeb 7.6.0, FortiWeb 7.4.0 through 7.4.4, FortiWeb 7.2 all versions, FortiWeb 7.0 all versions, FortiWeb 6.4 all versions allows attacker to disclose sensitive information via specially crafted packets.

A out-of-bounds write vulnerability [CWE-787] in FortiOS and FortiProxy may allow a remote unauthenticated attacker to execute arbitrary code or command via specially crafted HTTP requests.

Workaround : disable SSL VPN (disable webmode is NOT a valid workaround)

Note: This is potentially being exploited in the wild.

A missing authentication for critical function vulnerability in Fortinet FortiManager 7.4.0 through 7.4.2, FortiManager 7.2.0 through 7.2.4, FortiManager 7.0.0 through 7.0.11, FortiManager 6.4.0 through 6.4.14, FortiOS 7.4.0 through 7.4.3, FortiOS 7.2.0 through 7.2.7, FortiOS 7.0.0 through 7.0.14, FortiOS 6.4 all versions, FortiOS 6.2 all versions, FortiOS 6.0 all versions, FortiPAM 1.2 all versions, FortiPAM 1.1 all versions, FortiPAM 1.0 all versions, FortiPortal 6.0.0 through 6.0.14, FortiPortal 5.3 all versions, FortiProxy 7.4.0 through 7.4.3, FortiProxy 7.2.0 through 7.2.9, FortiProxy 7.0.0 through 7.0.16, FortiProxy 2.0 all versions, FortiProxy 01.02 all versions, FortiProxy 1.2 all versions, FortiProxy 01.01 all versions, FortiProxy 1.1 all versions, FortiProxy 01.00 all versions, FortiSwitchManager 7.2.0 through 7.2.3, FortiSwitchManager 7.0.0 through 7.0.3 allows attacker to execute unauthorized code or commands via specially crafted packets.

A improper limitation of a pathname to a restricted directory ('path traversal') vulnerability in Fortinet FortiManager 7.6.0 through 7.6.1, FortiManager 7.4.1 through 7.4.3, FortiManager Cloud 7.4.1 through 7.4.3, FortiOS 7.6.0, FortiOS 7.4.0 through 7.4.4, FortiOS 7.2.0 through 7.2.9, FortiOS 7.0.0 through 7.0.15, FortiOS 6.4.0 through 6.4.15, FortiProxy 7.4.0 through 7.4.5, FortiProxy 7.2.0 through 7.2.11, FortiProxy 7.0.0 through 7.0.18, FortiProxy 2.0 all versions, FortiProxy 01.02 all versions, FortiProxy 1.2 all versions, FortiProxy 01.01 all versions, FortiProxy 1.1 all versions, FortiProxy 01.00 all versions may allow a remote authenticated attacker with access to the security fabric interface and port to write arbitrary files or a remote unauthenticated attacker to delete an arbitrary folder

A stack-based buffer overflow vulnerability in Fortinet FortiOS 7.4.0 through 7.4.3, FortiOS 7.2.0 through 7.2.7, FortiOS 7.0.0 through 7.0.14, FortiOS 6.4 all versions, FortiOS 6.2 all versions, FortiOS 6.0 all versions, FortiPAM 1.2 all versions, FortiPAM 1.1 all versions, FortiPAM 1.0 all versions, FortiProxy 7.4.0 through 7.4.3, FortiProxy 7.2.0 through 7.2.9, FortiProxy 7.0.0 through 7.0.16, FortiProxy 2.0 all versions, FortiProxy 01.02 all versions, FortiProxy 1.2 all versions, FortiProxy 01.01 all versions, FortiProxy 1.1 all versions, FortiProxy 01.00 all versions, FortiSwitchManager 7.2.0 through 7.2.3, FortiSwitchManager 7.0.1 through 7.0.3 allows attacker to execute unauthorized code or commands via specially crafted packets.

A use of externally-controlled format string vulnerability in Fortinet FortiOS 7.4.0, FortiOS 7.2.0 through 7.2.5, FortiOS 7.0 all versions, FortiOS 6.4 all versions, FortiOS 6.2 all versions, FortiPAM 1.1.0, FortiPAM 1.0 all versions, FortiProxy 7.2.0 through 7.2.5, FortiProxy 7.0.0 through 7.0.11, FortiProxy 2.0 all versions, FortiProxy 01.02 all versions, FortiProxy 1.2 all versions, FortiProxy 01.01 all versions, FortiProxy 1.1 all versions, FortiSwitchManager 7.2.0 through 7.2.2, FortiSwitchManager 7.0.0 through 7.0.2 allows attacker to execute unauthorized code or commands via specially crafted cli commands and http requests.

A insufficiently protected credentials vulnerability in Fortinet FortiOS 7.4.0 through 7.4.1, FortiOS 7.2.0 through 7.2.6, FortiOS 7.0.0 through 7.0.12, FortiOS 6.4.0 through 6.4.14, FortiOS 6.2.0 through 6.2.15, FortiOS 6.0 all versions, FortiProxy 7.4.0 through 7.4.1, FortiProxy 7.2.0 through 7.2.7, FortiProxy 7.0.0 through 7.0.13, FortiProxy 2.0 all versions, FortiProxy 01.02 all versions, FortiProxy 1.2 all versions, FortiProxy 01.01 all versions, FortiProxy 1.1 all versions, FortiProxy 01.00 all versions allows attacker to execute unauthorized code or commands via targeted social engineering attack

A null pointer dereference [CWE-476] in FortiOS and FortiProxy SSL VPN may allow an authenticated attacker to perform a DoS attack on the device via specifically crafted HTTP requests.

A use of externally-controlled format string vulnerability in Fortinet FortiOS 7.4.0, FortiOS 7.2.0 through 7.2.5, FortiOS 7.0 all versions, FortiOS 6.4 all versions, FortiOS 6.2 all versions, FortiOS 6.0.0 through 6.0.16, FortiPAM 1.1.0, FortiPAM 1.0 all versions, FortiProxy 7.2.0 through 7.2.5, FortiProxy 7.0.0 through 7.0.11, FortiProxy 2.0 all versions, FortiProxy 01.02 all versions, FortiProxy 1.2 all versions, FortiProxy 01.01 all versions, FortiProxy 1.1 all versions, FortiProxy 01.00 all versions allows attacker to execute unauthorized code or commands via specially crafted commands

A use of externally-controlled format string vulnerability in Fortinet FortiOS 7.2.0 through 7.2.4, FortiOS 7.0.0 through 7.0.11, FortiOS 6.4.0 through 6.4.12, FortiOS 6.2.0 through 6.2.14, FortiOS 6.0.0 through 6.0.16, FortiOS 5.6 all versions, FortiOS 5.4 all versions, FortiOS 5.2 all versions, FortiOS 5.0 all versions, FortiOS 4.3 all versions, FortiOS 4.2 all versions, FortiOS 4.1 all versions, FortiOS 4.0 all versions, FortiPAM 1.0 all versions, FortiProxy 7.2.0 through 7.2.4, FortiProxy 7.0.0 through 7.0.10, FortiProxy 2.0.0 through 2.0.12, FortiProxy 01.02 all versions, FortiProxy 1.2 all versions, FortiProxy 01.01 all versions, FortiProxy 1.1 all versions, FortiProxy 01.00 all versions allows attacker to execute unauthorized code or commands via specially crafted command.

A null pointer dereference vulnerability in Fortinet FortiOS 7.2.0 through 7.2.4, FortiOS 7.0.0 through 7.0.11, FortiOS 6.4.0 through 6.4.12, FortiOS 6.2.0 through 6.2.14, FortiOS 6.0.0 through 6.0.16, FortiProxy 7.2.0 through 7.2.3, FortiProxy 7.0.0 through 7.0.10, FortiProxy 2.0.0 through 2.0.12, FortiProxy 01.02 all versions, FortiProxy 1.2 all versions, FortiProxy 01.01 all versions, FortiProxy 1.1 all versions, FortiProxy 01.00 all versions allows attacker to denial of service via specially crafted HTTP requests.

A access of uninitialized pointer vulnerability [CWE-824] in Fortinet FortiProxy version 7.2.0 through 7.2.3 and before 7.0.9 and FortiOS version 7.2.0 through 7.2.4 and before 7.0.11 allows an authenticated attacker to repetitively crash the httpsd process via crafted HTTP or HTTPS requests.

A out-of-bounds write in Fortinet FortiOS version 7.2.0 through 7.2.3, FortiOS version 7.0.0 through 7.0.10, FortiOS version 6.4.0 through 6.4.11, FortiOS version 6.2.0 through 6.2.13, FortiOS all versions 6.0, FortiProxy version 7.2.0 through 7.2.1, FortiProxy version 7.0.0 through 7.0.7, FortiProxy all versions 2.0, FortiProxy all versions 1.2, FortiProxy all versions 1.1, FortiProxy all versions 1.0 allows an authenticated attacker to execute unauthorized code or commands via specifically crafted requests.

A relative path traversal vulnerability [CWE-23] in Fortinet FortiOS version 7.2.0 through 7.2.2, 7.0.0 through 7.0.8 and before 6.4.11, FortiProxy version 7.2.0 through 7.2.2 and 7.0.0 through 7.0.8 allows privileged VDOM administrators to escalate their privileges to super admin of the box via crafted CLI requests.

A improper neutralization of crlf sequences in http headers ('http response splitting') in Fortinet FortiOS versions 7.2.0 through 7.2.2, 7.0.0 through 7.0.8, 6.4.0 through 6.4.11, 6.2.0 through 6.2.12, 6.0.0 through 6.0.16, FortiProxy 7.2.0 through 7.2.1, 7.0.0 through 7.0.7, 2.0.0 through 2.0.10, 1.2.0 through 1.2.13, 1.1.0 through 1.1.6 may allow an authenticated and remote attacker to perform an HTTP request splitting attack which gives attackers control of the remaining headers and body of the response.

An Internal Asset Exposed to Unsafe Debug Access Level or State vulnerability [CWE-1244] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.2, FortiOS 7.4.0 through 7.4.7, FortiOS 7.2.0 through 7.2.10, FortiOS 7.0.0 through 7.0.16, FortiOS 6.4 all versions, FortiProxy 7.6.0 through 7.6.3, FortiProxy 7.4.0 through 7.4.10, FortiProxy 7.2.0 through 7.2.14, FortiProxy 7.0 all versions may allow an authenticated admin to execute lua scripts via crafted CLI commands.

An improper verification of cryptographic signature vulnerability in Fortinet FortiWeb 8.0.0, FortiWeb 7.6.0 through 7.6.4, FortiWeb 7.4.0 through 7.4.9 may allow an unauthenticated attacker to bypass the FortiCloud SSO login authentication via a crafted SAML response message.

A improper verification of cryptographic signature vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11, FortiOS 7.0.0 through 7.0.17, FortiProxy 7.6.0 through 7.6.3, FortiProxy 7.4.0 through 7.4.10, FortiProxy 7.2.0 through 7.2.14, FortiProxy 7.0.0 through 7.0.21, FortiSwitchManager 7.2.0 through 7.2.6, FortiSwitchManager 7.0.0 through 7.0.5 allows an unauthenticated attacker to bypass the FortiCloud SSO login authentication via a crafted SAML response message.

A out-of-bounds write vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11 allows attacker to execute unauthorized code or commands via specially crafted packets.

An Improper Validation of Certificate with Host Mismatch vulnerability [CWE-297] in FortiProxy version 7.6.1 and below, version 7.4.8 and below, 7.2 all versions, 7.0 all versions and FortiOS version 7.6.2 and below, version 7.4.8 and below, 7.2 all versions, 7.0 all versions ZTNA proxy may allow an unauthenticated attacker in a man-in-the middle position to intercept and tamper with connections to the ZTNA proxy

A heap-based buffer overflow vulnerability [CWE-122] in FortiOS and FortiSwitchManager cwacd daemon may allow a remote unauthenticated attacker to execute arbitrary code or commands via specifically crafted requests.The presence of security controls such as ASLR and PIE considerably raises the complexity and preparation effort required for exploitation.

A storing passwords in a recoverable format in Fortinet FortiOS 7.4.0 through 7.4.8, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions allows attacker to information disclosure via modification of LDAP server IP to point to a malicious server.

An Insufficient Session Expiration vulnerability [CWE-613] in FortiOS SSL VPN 7.6.0 through 7.6.2, 7.4.0 through 7.4.6, 7.2.0 through 7.2.10, 7.0.0 through 7.0.16, 6.4 all versions may allow a remote attacker (e.g. a former admin whose account was removed and whose session was terminated) in possession of the SAML record of a user session to access or re-open that session via re-use of SAML record.

An Incorrect Provision of Specified Functionality vulnerability [CWE-684] in FortiOS 7.6.0, 7.4.0 through 7.4.5, 7.2.5 through 7.2.10, 7.0.0 through 7.0.15, 6.4 all versions may allow a local authenticated attacker to execute system commands via crafted CLI commands.

A missing authentication for critical function vulnerability [CWE-306] in FortiOS and FortiSwitchManager CAPWAP daemon may allow a local unauthenticated attacker on the same local IP subnet to write device configuration via specially crafted requests. To be successful, this attack requires the targeted FortiGate device to run a specific, non default configuration.

A session fixation vulnerability [CWE-384] in FortiOS may allow an unauthenticated attacker to hijack user session via a phishing SAML authentication link.

An authentication bypass using an alternate path or channel [CWE-288] in Fortinet FortiOS version 7.2.0 through 7.2.1 and 7.0.0 through 7.0.6, FortiProxy version 7.2.0 and version 7.0.0 through 7.0.6 and FortiSwitchManager version 7.2.0 and 7.0.0 allows an unauthenticated atttacker to perform operations on the administrative interface via specially crafted HTTP or HTTPS requests.