FreshPorts - VuXML

Simon Tatham reports:

PuTTY version 0.80 [contains] one security fix [...] for a newly discovered security issue known as the 'Terrapin' attack, also numbered CVE-2023-48795. The issue affects widely-used OpenSSH extensions to the SSH protocol: the ChaCha20+Poly1305 cipher system, and 'encrypt-then-MAC' mode.

In order to benefit from the fix, you must be using a fixed version of PuTTY _and_ a server with the fix, so that they can agree to adopt a modified version of the protocol. [...]

< 0.80

< 0.80

Simon Tatham reports:

[Release 0.74] fixes the following security issues:

• New configuration option to disable PuTTY's default policy of changing its host key algorithm preferences to prefer keys it already knows. (There is a theoretical information leak in this policy.) [CVE-2020-14002]
• In some situations an SSH server could cause PuTTY to access freed mdmory by pretending to accept an SSH key and then refusing the actual signature. It can only happen if you're using an SSH agent.

< 0.74

< 0.74

< 0.74

Simon Tatham reports:

Vulnerabilities fixed in this release include:

• A malicious SSH-1 server could trigger a buffer overrun by sending extremely short RSA keys, or certain bad packet length fields. Either of these could happen before host key verification, so even if you trust the server you *intended* to connect to, you would still be at risk.
  
  (However, the SSH-1 protocol is obsolete, and recent versions of PuTTY do not try it by default, so you are only at risk if you work with old servers and have explicitly configured SSH-1.)
• If a malicious process found a way to impersonate Pageant, then it could cause an integer overflow in any of the SSH client tools (PuTTY, Plink, PSCP, PSFTP) which accessed the malicious Pageant.

Other security-related bug fixes include:

• The 'trust sigil' system introduced in PuTTY 0.71 to protect against server spoofing attacks had multiple bugs. Trust sigils were not turned off after login in the SSH-1 and Rlogin protocols, and not turned back on if you used the Restart Session command. Both are now fixed.

< 0.72

< 0.72

< 0.72

The PuTTY team reports:

New in 0.71:

• Security fixes found by an EU-funded bug bounty programme:
• + a remotely triggerable memory overwrite in RSA key exchange, which can occur before host key verification
• + potential recycling of random numbers used in cryptography
• + on Unix, remotely triggerable buffer overflow in any kind of server-to-client forwarding
• + multiple denial-of-service attacks that can be triggered by writing to the terminal
• Other security enhancements: major rewrite of the crypto code to remove cache and timing side channels.
• User interface changes to protect against fake authentication prompts from a malicious server.

< 0.71

< 0.71

< 0.71

Simon Tatham reports:

ECDSA signatures using 521-bit keys (the NIST P521 curve, otherwise known as ecdsa-sha2-nistp521) were generated with biased random numbers. This permits an attacker in possession of a few dozen signatures to RECOVER THE PRIVATE KEY.

Any 521-bit ECDSA private key that PuTTY or Pageant has used to sign anything should be considered compromised.

Additionally, if you have any 521-bit ECDSA private keys that you've used with PuTTY, you should consider them to be compromised: generate new keys, and remove the old public keys from any authorized_keys files.

A second, independent scenario is that the adversary is an operator of an SSH server to which the victim authenticates (for remote login or file copy), [...] and the victim uses the same private key for SSH connections to other services operated by other entities. Here, the rogue server operator (who would otherwise have no way to determine the victim's private key) can derive the victim's private key, and then use it for unauthorized access to those other services. If the other services include Git services, then again it may be possible to conduct supply-chain attacks on software maintained in Git. This also affects, for example, FileZilla before 3.67.0, WinSCP before 6.3.3, TortoiseGit before 2.15.0.1, and TortoiseSVN through 1.14.6.

ge 0.68 lt 0.81

ge 0.68 lt 0.81

< 3.67.0