In PuTTY 0.68 through 0.80 before 0.81, biased ECDSA nonce generation allows an attacker to recover a user's NIST P-521 secret key via a quick attack in approximately 60 signatures. This is especially important in a scenario where an adversary is able to read messages signed by PuTTY or Pageant. The required set of signed messages may be publicly readable because they are stored in a public Git service that supports use of SSH for commit signing, and the signatures were made by Pageant through an agent-forwarding mechanism. In other words, an adversary may already have enough signature information to compromise a victim's private key, even if there is no further use of vulnerable PuTTY versions. After a key compromise, an adversary may be able to conduct supply-chain attacks on software maintained in Git. 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), even though this server is not fully trusted by the victim, 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.

An issue was discovered in in TortoiseSVN 1.12.1. The Tsvncmd: URI handler allows a customised diff operation on Excel workbooks, which could be used to open remote workbooks without protection from macro security settings to execute arbitrary code. A tsvncmd:command:diff?path:[file1]?path2:[file2] URI will execute a customised diff on [file1] and [file2] based on the file extension. For xls files, it will execute the script diff-xls.js using wscript, which will open the two files for analysis without any macro security warning. An attacker can exploit this by putting a macro virus in a network drive, and force the victim to open the workbooks and execute the macro inside.

Untrusted search path vulnerability in TortoiseSVN 1.6.10, Build 19898 and earlier allows local users, and possibly remote attackers, to execute arbitrary code and conduct DLL hijacking attacks via a Trojan horse dwmapi.dll that is located in the same folder as a file that is processed by Tortoise. NOTE: this is only a vulnerability when a file extension is associated with TortoiseProc or TortoiseMerge, which is not the default.

Directory traversal vulnerability in Subversion before 1.4.5, as used by TortoiseSVN before 1.4.5 and possibly other products, when run on Windows-based systems, allows remote authenticated users to overwrite and create arbitrary files via a ..\ (dot dot backslash) sequence in the filename, as stored in the file repository.