An Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') [CWE-22] in the command line interpreter of FortiOS, FortiPAM, FortiProxy and FortiSwitchManager may allow a privileged attacker to achieve arbitrary write or delete files via specifically crafted arguments to existing commands.

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 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 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.

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.

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>

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.

An Exposure of Sensitive Information to an Unauthorized Actor vulnerability [CWE-200] vulnerability in Fortinet FortiOS 7.6.0, FortiOS 7.4.0 through 7.4.7, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions, FortiSASE 25.1.c may allow an authenticated user to access full SSL-VPN settings via crafted URL.

An Integer Overflow or Wraparound vulnerability [CWE-190] in FortiOS version 7.6.2 and below, version 7.4.7 and below, version 7.2.10 and below, 7.2 all versions, 6.4 all versions, FortiProxy version 7.6.2 and below, version 7.4.3 and below, 7.2 all versions, 7.0 all versions, 2.0 all versions and 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 SSL-VPN RDP and VNC bookmarks may allow an authenticated user to affect the device SSL-VPN availability via crafted requests.

An Improper Certificate Validation vulnerability [CWE-295] in FortiOS may allow an EAP verified remote user to connect from FortiClient via revoked certificate.

An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] in FortiOS 7.4.0 through 7.4.7, 7.2.0 through 7.2.11, 7.0.6 and above; and FortiProxy 7.6.0 through 7.6.2, 7.4.0 through 7.4.8, 7.2 all versions, 7.0.5 and above may allow an authenticated attacker to elevate their privileges via triggering a malicious Webhook action in the Automation Stitch component.

An Improperly Implemented Security Check for Standard vulnerability [CWE-358] in FortiOS and FortiProxy may allow a remote unauthenticated user to bypass the DNS filter via Apple devices.

A out-of-bounds write in Fortinet FortiOS versions 7.6.0, 7.4.0 through 7.4.6, 7.2.0 through 7.2.10, 7.0.0 through 7.0.16, 6.4.0 through 6.4.15 allows attacker to trigger a denial of service via specially crafted packets.

An Insufficient Session Expiration vulnerability [CWE-613] in FortiOS SSL-VPN may allow an attacker in possession of a cookie used to log in the SSL-VPN portal to log in again, although the session has expired or was logged out.

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.

Accessibility. A privacy issue was addressed with improved private data redaction for log entries.

An Insufficient Session Expiration vulnerability [CWE-613] in FortiOS SSLVPN may allow an attacker to maintain access to network resources via an active session not terminated after a user's password change under particular conditions outside of the attacker's control

An improper access control vulnerability in Fortinet FortiSOAR PaaS 7.6.0 through 7.6.2, FortiSOAR PaaS 7.5.0 through 7.5.1, FortiSOAR PaaS 7.4 all versions, FortiSOAR PaaS 7.3 all versions, FortiSOAR on-premise 7.6.0 through 7.6.2, FortiSOAR on-premise 7.5.0 through 7.5.1, FortiSOAR on-premise 7.4 all versions, FortiSOAR on-premise 7.3 all versions may allow information disclosure to an authenticated attacker via crafted requests

An Incorrect Authorization vulnerability [CWE-863] in FortiPortal 7.4.0 through 7.4.5 may allow an authenticated attacker to reboot a shared FortiGate device via crafted HTTP requests.

An unverified password change vulnerability [CWE-620] vulnerability in Fortinet FortiSOAR PaaS 7.6.0 through 7.6.2, FortiSOAR PaaS 7.5.0 through 7.5.1, FortiSOAR PaaS 7.4 all versions, FortiSOAR PaaS 7.3 all versions, FortiSOAR on-premise 7.6.0 through 7.6.2, FortiSOAR on-premise 7.5.0 through 7.5.1, FortiSOAR on-premise 7.4 all versions, FortiSOAR on-premise 7.3 all versions may allow an attacker who has already gained access to a victim's user account to reset the account credentials without being prompted for the account's password