https://lists.mercurial-scm.org/pipermail/mercurial-packaging/2025-March/000754.html announces: Subject: Mercurial 6.9.4 tagged (CVE-2025-2361) From: Pierre-Yves David pierre-yves.david at octobus.net Date: Wed Mar 19 15:16:31 UTC 2025

This is an out of schedule security release

Please update your package builds, thanks.

This fixes a XSS vulnerability in hgweb, were an attacker could forge a link that would execute javascript in the target browser.

In practice in production setup, such injection might be caught by the wsgi layer.

For example the popular modewsgi would catch such injection and return a 500 instead:

https://github.com/GrahamDumpleton/modwsgi/blob/develop/src/server/wsgivalidate.c#L75

Thanks goes to Julien Cristau for noticing that such mitigation existed.

-- Pierre-Yves David https://lists.mercurial-scm.org/pipermail/mercurial-packaging/2025-March/000753.html adds:

Debian's security tracker points to this commit for further details: https://foss.heptapod.net/mercurial/mercurial-devel/-/commit/a5c72ed2929341d97b11968211c880854803f003

-- -Alan Coopersmith- alan.coopersmith () oracle com Oracle Solaris Engineering - https://blogs.oracle.com/solaris

A vulnerability was found in Mercurial SCM 4.5.3/71.19.145.211. It has been declared as problematic. This vulnerability affects unknown code of the component Web Interface. The manipulation of the argument cmd leads to cross site scripting. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Git before 1.8.5.6, 1.9.x before 1.9.5, 2.0.x before 2.0.5, 2.1.x before 2.1.4, and 2.2.x before 2.2.1 on Windows and OS X; Mercurial before 3.2.3 on Windows and OS X; Apple Xcode before 6.2 beta 3; mine all versions before 08-12-2014; libgit2 all versions up to 0.21.2; Egit all versions before 08-12-2014; and JGit all versions before 08-12-2014 allow remote Git servers to execute arbitrary commands via a tree containing a crafted .git/config file with (1) an ignorable Unicode codepoint, (2) a git~1/config representation, or (3) mixed case that is improperly handled on a case-insensitive filesystem.

Mercurial before 1.6.4 fails to verify the Common Name field of SSL certificates which allows remote attackers who acquire a certificate signed by a Certificate Authority to perform a man-in-the-middle attack.

A flaw was found in Mercurial before 4.9. It was possible to use symlinks and subrepositories to defeat Mercurial's path-checking logic and write files outside a repository.

cext/manifest.c in Mercurial before 4.7.2 has an out-of-bounds read during parsing of a malformed manifest entry.

The mpatchdecode function in mpatch.c in Mercurial before 4.6.1 mishandles certain situations where there should be at least 12 bytes remaining after the current position in the patch data, but actually are not, aka OVE-20180430-0001.

Mercurial before version 4.6.1 has a missing check for fragment start position in mpatch.c:mpatchapply()

Upstream Changelog:

https://www.mercurial-scm.org/wiki/WhatsNew#Mercurial4.6.1.282018-06-06.29

Upstream Patch:

https://www.mercurial-scm.org/repo/hg/rev/faa924469635

mpatch.c in Mercurial before 4.6.1 mishandles integer addition and subtraction, aka OVE-20180430-0002.

Mercurial version 4.5 and earlier contains a Incorrect Access Control (CWE-285) vulnerability in Protocol server that can result in Unauthorized data access. This attack appear to be exploitable via network connectivity. This vulnerability appears to have been fixed in 4.5.1.

In Mercurial before 4.4.1, it is possible that a specially malformed repository can cause Git subrepositories to run arbitrary code in the form of a .git/hooks/post-update script checked into the repository. Typical use of Mercurial prevents construction of such repositories, but they can be created programmatically.

Mercurial prior to version 4.3 is vulnerable to a missing symlink check that can malicious repositories to modify files outside the repository

Mercurial clients sometimes connect to URLs provided by the repository, as subrepositories, via the .hgsub file.

A maliciously constructed ssh:// URL would cause Mercurial clients to run an arbitrary shell command. Such a URL could be generated by a malicious server, by a malicious user committing to a honest server (to attack another user of that server's repositories), or by a proxy server.

The vulnerability affects all clients, including those that use file://, http://, and ssh://.

In Mercurial before 4.1.3, "hg serve --stdio" allows remote authenticated users to launch the Python debugger, and consequently execute arbitrary code, by using --debugger as a repository name.

The convert extension in Mercurial before 3.8 might allow context-dependent attackers to execute arbitrary code via a crafted git repository name.

Mercurial before 3.7.3 allows remote attackers to execute arbitrary code via a crafted name when converting a Git repository.

Mercurial before 3.7.3 allows remote attackers to execute arbitrary code via a crafted git ext:: URL when cloning a subrepository.

The binary delta decoder in Mercurial before 3.7.3 allows remote attackers to execute arbitrary code via a (1) clone, (2) push, or (3) pull command, related to (a) a list sizing rounding error and (b) short records.

The validaterepo function in sshpeer in Mercurial before 3.2.4 allows remote attackers to execute arbitrary commands via a crafted repository name in a clone command.

Mercurial before 1.0.2 does not enforce the allowpull permission setting for a pull operation from hgweb, which allows remote attackers to read arbitrary files from a repository via an "hg pull" request.

Directory traversal vulnerability in patch.py in Mercurial 1.0.1 allows user-assisted attackers to modify arbitrary files via ".." (dot dot) sequences in a patch file.