A buffer copy without checking size of input ('classic buffer overflow') vulnerability in Fortinet FortiClientWindows 7.4.0 through 7.4.3, FortiClientWindows 7.2.0 through 7.2.11 may allow an unauthenticated attacker in a position to alter or craft DNS responses to the targeted host to execute arbitrary code via malicious packets.

An Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability [CWE-89] vulnerability in Fortinet FortiAnalyzer 7.6.0 through 7.6.4, FortiAnalyzer 7.4.0 through 7.4.7, FortiAnalyzer 7.2 all versions, FortiAnalyzer Cloud 7.6.2 through 7.6.4, FortiAnalyzer Cloud 7.4.1 through 7.4.7, FortiAnalyzer Cloud 7.2.1 through 7.2.11 may allow a low privileged user to execute arbitrary commands via crafted requests.

An improper neutralization of special elements used in an SQL Command ("SQL Injection") vulnerability [CWE-89] vulnerability in Fortinet FortiMail 7.6.0 through 7.6.3, FortiMail 7.4.0 through 7.4.5, FortiMail 7.2.0 through 7.2.8 allows an authenticated attacker to execute unauthorized code or commands via specifically crafted HTTP or HTTPS requests.

A security regression (CVE-2006-5051) was discovered in OpenSSH's server (sshd). There is a race condition which can lead sshd to handle some signals in an unsafe manner. An unauthenticated, remote attacker may be able to trigger it by failing to authenticate within a set time period.

A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages. It is only freed when the server/client key exchange has finished. A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side. Consequently, the server may become unavailable, resulting in a denial of service attack.

A improper validation of certificate with host mismatch vulnerability in Fortinet FortiOS 7.6.1 through 7.6.6, FortiProxy 7.6.2 through 7.6.6 may allow attacker to information disclosure via <insert attack vector here>

A NULL Pointer Dereference vulnerability [CWE-476] vulnerability in Fortinet FortiOS 7.4 all versions, FortiOS 7.2 all versions, FortiPAM 1.9.0, FortiPAM 1.8 all versions, FortiPAM 1.7 all versions, FortiPAM 1.6 all versions, FortiPAM 1.5 all versions, FortiPAM 1.4 all versions, FortiPAM 1.3 all versions, FortiPAM 1.2 all versions, FortiPAM 1.1 all versions, FortiPAM 1.0 all versions, FortiProxy 7.6.0 through 7.6.6, FortiProxy 7.4 all versions, FortiProxy 7.2 all versions may allow an authenticated attacker to crash the httpsd daemon via crafted HTTP requests.

A allocation of resources without limits or throttling vulnerability in Fortinet FortiOS 7.6.0 through 7.6.6, FortiOS 7.4 all versions, FortiOS 7.2 all versions may allow attacker to denial of service via <insert attack vector here>

A Stack-based Buffer Overflow vulnerability [CWE-121] vulnerability in Fortinet FortiOS 7.6.1 through 7.6.6 may allow an unauthenticated attacker who can bypass stack protection and ASLR to execute arbitrary code or commands in the context of the WAD daemon via crafted sockets, only if the explicit proxy is configured with Kerberos authentication and SOCKS enabled.

A buffer over-read vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions, FortiProxy 7.6.0 through 7.6.5, FortiProxy 7.4.0 through 7.4.13, FortiProxy 7.2 all versions, FortiProxy 7.0 all versions may allow attacker to information disclosure via <insert attack vector here>

A improper limitation of a pathname to a restricted directory ('path traversal') vulnerability in Fortinet FortiOS 7.6.0 through 7.6.6, FortiOS 7.4.0 through 7.4.9, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions, FortiPAM 1.8.0, FortiPAM 1.7.0 through 1.7.2, FortiPAM 1.6 all versions, FortiPAM 1.5 all versions, FortiPAM 1.4 all versions, FortiPAM 1.3 all versions, FortiPAM 1.2 all versions, FortiPAM 1.1 all versions, FortiPAM 1.0 all versions, FortiProxy 7.6.0 through 7.6.5, FortiProxy 7.4 through 7.4.13, FortiProxy 7.2 all versions, FortiProxy 7.0 all versions may allow attacker to execute unauthorized code or commands via <insert attack vector here>

A stack-based buffer overflow vulnerability in Fortinet FortiOS 7.4.0 through 7.4.1, FortiOS 7.2 all versions, FortiPAM 1.8.0 through 1.8.2, FortiPAM 1.7 all versions, FortiPAM 1.6 all versions, FortiPAM 1.5 all versions, FortiPAM 1.4 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 7.4.13, FortiProxy 7.2 all versions may allow a privileged authenticated attacker who can bypass stack protection and ASLR to execute arbitrary code or commands via crafted HTTP requests.

A fundamental design flaw within the RADIUS protocol has been proven to be exploitable, compromising the integrity in the RADIUS Access-Request process. The attack allows a malicious user to modify packets in a way that would be indistinguishable to a RADIUS client or server. To be successful, the attacker must have the ability to inject themselves between the client and server.

Summary

Terrapin is a prefix truncation attack targeting the SSH protocol. More precisely, Terrapin breaks the integrity of SSH's secure channel. By carefully adjusting the sequence numbers during the handshake, an attacker can remove an arbitrary amount of messages sent by the client or server at the beginning of the secure channel without the client or server noticing it.

Mitigations

To mitigate this protocol vulnerability, OpenSSH suggested a so-called "strict kex" which alters the SSH handshake to ensure a Man-in-the-Middle attacker cannot introduce unauthenticated messages as well as convey sequence number manipulation across handshakes.

Warning: To take effect, both the client and server must support this countermeasure.

As a stop-gap measure, peers may also (temporarily) disable the affected algorithms and use unaffected alternatives like AES-GCM instead until patches are available.

Details

The SSH specifications of ChaCha20-Poly1305 (chacha20-poly1305@openssh.com) and Encrypt-then-MAC (-etm@openssh.com MACs) are vulnerable against an arbitrary prefix truncation attack (a.k.a. Terrapin attack). This allows for an extension negotiation downgrade by stripping the SSHMSGEXTINFO sent after the first message after SSHMSGNEWKEYS, downgrading security, and disabling attack countermeasures in some versions of OpenSSH. When targeting Encrypt-then-MAC, this attack requires the use of a CBC cipher to be practically exploitable due to the internal workings of the cipher mode. Additionally, this novel attack technique can be used to exploit previously unexploitable implementation flaws in a Man-in-the-Middle scenario.

The attack works by an attacker injecting an arbitrary number of SSHMSGIGNORE messages during the initial key exchange and consequently removing the same number of messages just after the initial key exchange has concluded. This is possible due to missing authentication of the excess SSHMSGIGNORE messages and the fact that the implicit sequence numbers used within the SSH protocol are only checked after the initial key exchange.

In the case of ChaCha20-Poly1305, the attack is guaranteed to work on every connection as this cipher does not maintain an internal state other than the message's sequence number. In the case of Encrypt-Then-MAC, practical exploitation requires the use of a CBC cipher; while theoretical integrity is broken for all ciphers when using this mode, message processing will fail at the application layer for CTR and stream ciphers.

For more details see https://terrapin-attack.com.

Impact

This attack targets the specification of ChaCha20-Poly1305 (chacha20-poly1305@openssh.com) and Encrypt-then-MAC (-etm@openssh.com), which are widely adopted by well-known SSH implementations and can be considered de-facto standard. These algorithms can be practically exploited; however, in the case of Encrypt-Then-MAC, we additionally require the use of a CBC cipher. As a consequence, this attack works against all well-behaving SSH implementations supporting either of those algorithms and can be used to downgrade (but not fully strip) connection security in case SSH extension negotiation (RFC8308) is supported. The attack may also enable attackers to exploit certain implementation flaws in a man-in-the-middle (MitM) scenario.

An Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability [CWE-79] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.6, FortiOS 7.4 all versions, FortiOS 7.2 all versions, FortiPAM 1.8.0, FortiPAM 1.7 all versions, FortiPAM 1.6 all versions, FortiPAM 1.5 all versions, FortiPAM 1.4 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 7.4.3, FortiProxy 7.2.0 through 7.2.9 may allow an authenticated remote user to execute code or commands via crafted requests.

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 Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting') vulnerability [CWE-113] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.4, FortiOS 7.4 all versions, FortiOS 7.2 all versions, FortiProxy 7.6.0 through 7.6.4, FortiProxy 7.4 all versions, FortiProxy 7.2 all versions may allow an attacker able to intercept and modify a user's captive portal authentication request to inject arbitrary headers via crafted HTTP requests.

An Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting') vulnerability [CWE-113] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.4, FortiOS 7.4 all versions, FortiOS 7.2 all versions, FortiProxy 7.6.0 through 7.6.4, FortiProxy 7.4 all versions, FortiProxy 7.2 all versions may allow an attacker in possession of a valid web filter override token to inject arbitrary headers via tricking a user into clicking on a crafted link.

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.

An Unchecked Return Value vulnerability [CWE-252] in Fortinet FortiOS version 7.6.0 through 7.6.3 and before 7.4.8 API allows an authenticated user to cause a Null Pointer Dereference, crashing the http daemon via a specialy crafted request.

A stack-based buffer overflow vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions, FortiOS 6.2 all versions, FortiOS 6.0 all versions, FortiSASE 25.3.b allows attacker to execute unauthorized code or commands via specially crafted packets

An Heap-based Buffer Overflow vulnerability [CWE-122] in FortiOS version 7.6.2 and below, version 7.4.7 and below, version 7.2.10 and below, 7.0 all versions, 6.4 all versions; FortiPAM version 1.5.0, version 1.4.2 and below, 1.3 all versions, 1.2 all versions, 1.1 all versions, 1.0 all versions and FortiProxy version 7.6.2 and below, version 7.4.3 and below, 7.2 all versions, 7.0 all versions RDP bookmark connection may allow an authenticated user to execute unauthorized code via crafted requests.

An Improper Privilege Management vulnerability [CWE-269] in FortiOS, FortiProxy and FortiPAM may allow an authenticated administrator to bypass the trusted host policy via crafted CLI command.

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.

A stack-based buffer overflow vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, 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 execute unauthorized code or commands via specially crafted packets

An incorrect privilege assignment vulnerability [CWE-266] in FortiOS Security Fabric may allow a remote authenticated attacker with high privileges to escalate their privileges to super-admin via registering the device to a malicious FortiManager.

An Improper Neutralization of Input During Web Page Generation and URL Redirection to Untrusted Site vulnerabilities [CWE-79, CWE-601] in FortiOS, FortiProxy and FortiSASE may allow an unauthenticated attacker to perform a reflected cross site scripting (XSS) or an open redirect attack via crafted HTTP requests.

A buffer over-read vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions may allow an authenticated remote attacker to return a portion of device memory in the redirect response via submitting a specially crafted request.

A insertion of sensitive information into log file vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4 all versions, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions, FortiProxy 7.6.0 through 7.6.3, FortiProxy 7.4.0 through 7.4.13, FortiProxy 7.2 all versions, FortiProxy 7.0 all versions may allow attacker to information disclosure via <insert attack vector here>