#ssh

By Deeba Ahmed The 8220 gang, believed to be of Chinese origins, was first identified in 2017 by Cisco Talos when they targeted Drupal, Hadoop YARN, and Apache Struts2 applications for propagating cryptojacking malware. This is a post from HackRead.com Read the original post: 8220 Gang Targets Telecom and Healthcare in Global Cryptojacking Attack

Ubuntu Security Notice 6561-1 - Fabian Bäumer, Marcus Brinkmann, Joerg Schwenk discovered that the SSH protocol was vulnerable to a prefix truncation attack. If a remote attacker was able to intercept SSH communications, extension negotiation messages could be truncated, possibly leading to certain algorithms and features being downgraded. This issue is known as the Terrapin attack. This update adds protocol extensions to mitigate this issue.

Ubuntu Security Notice 6560-1 - Fabian Bäumer, Marcus Brinkmann, Joerg Schwenk discovered that the SSH protocol was vulnerable to a prefix truncation attack. If a remote attacker was able to intercept SSH communications, extension negotiation messages could be truncated, possibly leading to certain algorithms and features being downgraded. This issue is known as the Terrapin attack. This update adds protocol extensions to mitigate this issue. Luci Stanescu discovered that OpenSSH incorrectly added destination constraints when smartcard keys were added to ssh-agent, contrary to expectations. This issue only affected Ubuntu 22.04 LTS, and Ubuntu 23.04.

In this paper, the authors show that as new encryption algorithms and mitigations were added to SSH, the SSH Binary Packet Protocol is no longer a secure channel: SSH channel integrity (INT-PST) is broken for three widely used encryption modes. This allows prefix truncation attacks where some encrypted packets at the beginning of the SSH channel can be deleted without the client or server noticing it. They demonstrate several real-world applications of this attack. They show that they can fully break SSH extension negotiation (RFC 8308), such that an attacker can downgrade the public key algorithms for user authentication or turn off a new countermeasure against keystroke timing attacks introduced in OpenSSH 9.5. They also identified an implementation flaw in AsyncSSH that, together with prefix truncation, allows an attacker to redirect the victim's login into a shell controlled by the attacker. Related proof of concept code from their github has been added to this archive.

This is the second installment of the Azure Serial Console blog, which provides insights to improve defenders’ preparedness when investigating Azure Serial Console activity on Azure Linux virtual machines. While the first blog post discussed various tracing activities, such as using Azure activity and Sysmon logs on Windows virtual machines to trace serial console activity, this blog outlines how to enable logging for Azure Linux virtual machines using Sysmon for Linux to capture and how to send these events to a log analytics workspace.

### Summary Russh v0.40.1 and earlier is vulnerable to a novel prefix truncation attack (a.k.a. Terrapin attack), which allows a man-in-the-middle attacker to strip an arbitrary number of messages right after the initial key exchange, breaking SSH extension negotiation (RFC8308) in the process and thus downgrading connection security. ### 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. Support for strict key exchange has been added to Russh in the patched version. **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 Ch...

### Summary AsyncSSH v2.14.1 and earlier is vulnerable to a novel prefix truncation attack (a.k.a. Terrapin attack), which allows a man-in-the-middle attacker to strip an arbitrary number of messages right after the initial key exchange, breaking SSH extension negotiation (RFC8308) in the process and thus downgrading connection security. ### 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. Support for strict key exchange has been added to AsyncSSH in the patched version. **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...

By Waqas Polish authorities and FortiGuard Labs have issued a warning to customers about a new wave of cyberattacks associated with TeamCity. This is a post from HackRead.com Read the original post: Russian APT29 Hacked US Biomedical Giant in TeamCity-Linked Breach

As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global). View CSAF 1. EXECUTIVE SUMMARY CVSS v3 9.8 ATTENTION: Exploitable remotely/low attack complexity Vendor: Siemens Equipment: SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1 Vulnerabilities: Improper Restriction of XML External Entity Reference, Time-of-check Time-of-use (TOCTOU) Race Condition, Command Injection, Missing Encryption of Sensitive Data, Cross-site Scripting, Improper Restriction of Operations within the Bounds of a Memory Buffer, Use After Free, Improper Input Validation, Out-of-bounds Write, Out-of-bounds Read, Infinite Loop, Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection'), Allocation of Resources Without Limits or ...

As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global). View CSAF 1. EXECUTIVE SUMMARY CVSS v3 8.1 ATTENTION: Exploitable remotely/low attack complexity Vendor: Siemens Equipment: SINEC INS Vulnerabilities: Improper Certificate Validation, Improper Input Validation, Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'), Unexpected Status Code or Return Value, Missing Report of Error Condition, Improper Check for Unusual or Exceptional Conditions 2. RISK EVALUATION Successful exploitation of these vulnerabilities could allow an attacker to create a denial-of-service condition, intercept credentials, or escalate privileges on the affected device. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS The foll...