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.

Accessibility. A logic issue was addressed with improved checks.

Accounts. The issue was addressed with improved checks.

Accounts. The issue was addressed with improved checks.

Accounts. The issue was addressed with improved checks.

Accounts. The issue was addressed with improved checks.

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.

.NET Information Disclosure Vulnerability

.NET - SecurityFeatureBypass - Denial of Service and Security Feature Bypass via Unsafe Transforms in EncryptedXml

.NET - Denial Of Service - Denial of Service via Stack Overflow in EncryptedKey Nested Decryption

.NET - DenialOfService - Denial of Service via Infinite Recursion in XmlDecryptionTransform

.NET Spoofing Vulnerability

A vulnerability was found in openldap that can cause a null pointer dereference in the bermemallocx() function.

DNG SDK versions 1.7.0 and earlier are affected by an Integer Overflow or Wraparound vulnerability that could lead to application denial-of-service. An attacker could exploit this issue to cause the application to crash or become unresponsive. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

DNG SDK versions 1.7.0 and earlier are affected by a Heap-based Buffer Overflow vulnerability that could lead to memory exposure or application denial of service. An attacker could leverage this vulnerability to disclose sensitive memory information. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

DNG SDK versions 1.7.0 and earlier are affected by an Out-of-bounds Read vulnerability that could lead to memory exposure or application denial of service. An attacker could leverage this vulnerability to disclose sensitive information stored in memory. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

DNG SDK versions 1.7.0 and earlier are affected by an Integer Overflow or Wraparound vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Foxit PDF Editor and Reader before 2025.2.1 allow signature spoofing via triggers. An attacker can embed triggers (e.g., JavaScript) in a PDF document that execute during the signing process. When a signer reviews the document, the content appears normal. However, once the signature is applied, the triggers modify content on other pages or optional content layers without explicit warning. This can cause the signed PDF to differ from what the signer saw, undermining the trustworthiness of the digital signature. The fixed versions are 2025.2.1, 14.0.1, and 13.2.1.

Foxit PDF Editor and Reader before 2025.2.1 allow signature spoofing via OCG. When Optional Content Groups (OCG) are supported, the state property of an OCG is runtime-only and not included in the digital signature computation buffer. An attacker can leverage JavaScript or PDF triggers to dynamically change the visibility of OCG content after signing (Post-Sign), allowing the visual content of a signed PDF to be modified without invalidating the signature. This may result in a mismatch between the signed content and what the signer or verifier sees, undermining the trustworthiness of the digital signature. The fixed versions are 2025.2.1, 14.0.1, and 13.2.1.

An issue was discovered in Foxit PDF and Editor for Windows and macOS before 13.2 and 2025 before 2025.2. They allow potential arbitrary code execution when processing crafted PDF files. The vulnerability stems from insufficient handling of memory allocation failures after assigning an extremely large value to a form field's charLimit property via JavaScript. This can result in memory corruption and may allow an attacker to execute arbitrary code by persuading a user to open a malicious file.

An issue was discovered in Foxit PDF and Editor for Windows before 13.2 and 2025 before 2025.2. When pages in a PDF are deleted via JavaScript, the application may fail to properly update internal states. Subsequent annotation management operations assume these states are valid, causing dereference of invalid or released memory. This can lead to memory corruption, application crashes, and potentially allow an attacker to execute arbitrary code.

An issue was discovered in Foxit PDF and Editor for Windows and macOS before 13.2 and 2025 before 2025.2. An attacker able to alter or replace the static HTML files used by the StartPage feature can cause the application to load malicious or compromised content upon startup. This may result in information disclosure, unauthorized data access, or other security impacts.

An issue was discovered in Foxit PDF and Editor for Windows and macOS before 13.2 and 2025 before 2025.2. A crafted PDF can contain JavaScript that attaches an OnBlur action on a form field that destroys an annotation. During user right-click interaction, the program's internal focus change handling prematurely releases the annotation object, resulting in a use-after-free vulnerability that may cause memory corruption or application crashes.

An issue was discovered in Foxit PDF and Editor for Windows and macOS before 13.2 and 2025 before 2025.2. A crafted PDF can use JavaScript to alter annotation content and subsequently clear the file's modification status via JavaScript interfaces. This circumvents digital signature verification by hiding document modifications, allowing an attacker to mislead users about the document's integrity and compromise the trustworthiness of signed PDFs.

A type confusion vulnerability in Palo Alto Networks GlobalProtect™ app on Windows enables a local user with low privileges to cause a denial of service (DoS) condition.

The GlobalProtect™ app on Linux, macOS, iOS, Android, and Chrome OS is not affected by this vulnerability.

A local privilege escalation vulnerability in the Palo Alto Networks GlobalProtect™ app enables a local user to escalate their privileges to root on macOS. This enables a non-administrative user to execute arbitrary commands with administrative privileges.

The GlobalProtect app on Linux, Windows, iOS, Android and Chrome OS is not affected by this vulnerability.

A use after free vulnerability exists in curl <7.87.0. Curl can be asked to tunnel virtually all protocols it supports through an HTTP proxy. HTTP proxies can (and often do) deny such tunnel operations. When getting denied to tunnel the specific protocols SMB or TELNET, curl would use a heap-allocated struct after it had been freed, in its transfer shutdown code path.

A vulnerability was found in curl. The issue occurs if curl is told to use an HTTP proxy for a transfer with a non-HTTP(S) URL. It sets up the connection to the remote server by issuing a CONNECT request to the proxy and then tunnels the rest of the protocol through. An HTTP proxy might refuse this request (HTTP proxies often only allow outgoing connections to specific port numbers, like 443 for HTTPS) and instead return a non-200 response code to the client. Due to flaws in the error/cleanup handling, this could trigger a double-free issue in curl if using one of the following schemes in the URL for the transfer: dict, gopher, gophers, ldap, ldaps, rtmp, rtmps, telnet.

A vulnerability was found in curl. The issue occurs because curl's HSTS check can be bypassed to trick it to keep using HTTP. Using its HSTS support, it can instruct curl to use HTTPS directly instead of using an insecure clear-text HTTP step even when HTTP is provided in the URL. This mechanism can be bypassed if the hostname in the given URL uses IDN characters that get replaced with ASCII counterparts as part of the IDN conversion. Like using the character UTF-8 U+3002 (IDEOGRAPHIC FULL STOP) instead of the common ASCII full stop (U+002E) ..

A flaw was found in libxml2. When a reference cycle is detected in the XML entity cleanup function the XML entity data can be stored in a dictionary. In this case, the dictionary becomes corrupted resulting in logic errors, including memory errors like double free.