Merge pull request from GHSA-8fjr-hghr-4m99

Release 1.2.5 incl. archives TAM security fix

docs/changes.rst

@@ -5,6 +5,72 @@ Important notes
 
 This section provides information about security and corruption issues.
 
+.. _archives_tam_vuln:
+
+Pre-1.2.5 archives spoofing vulnerability (CVE-2023-36811)
+----------------------------------------------------------
+
+A flaw in the cryptographic authentication scheme in Borg allowed an attacker to
+fake archives and potentially indirectly cause backup data loss in the repository.
+
+The attack requires an attacker to be able to
+
+1. insert files (with no additional headers) into backups
+2. gain write access to the repository
+
+This vulnerability does not disclose plaintext to the attacker, nor does it
+affect the authenticity of existing archives.
+
+Creating plausible fake archives may be feasible for empty or small archives,
+but is unlikely for large archives.
+
+The fix enforces checking the TAM authentication tag of archives at critical
+places. Borg now considers archives without TAM as garbage or an attack.
+
+We are not aware of others having discovered, disclosed or exploited this vulnerability.
+
+Below, if we speak of borg 1.2.5, we mean a borg version >= 1.2.5 **or** a
+borg version that has the relevant security patches for this vulnerability applied
+(could be also an older version in that case).
+
+Steps you must take to upgrade a repository:
+
+1. Upgrade all clients using this repository to borg 1.2.5.
+   Note: it is not required to upgrade a server, except if the server-side borg
+   is also used as a client (and not just for "borg serve").
+
+   Do **not** run ``borg check`` with borg 1.2.5 before completing the upgrade steps.
+
+2. Run ``borg info --debug <repository> 2>&1 | grep TAM | grep -i manifest``.
+   a) If you get "TAM-verified manifest", continue with 3.
+   b) If you get "Manifest TAM not found and not required", run
+      ``borg upgrade --tam --force <repository>`` *on every client*.
+
+3. Run ``borg list --format='{name} {time} tam:{tam}{NL}' <repository>``.
+   "tam:verified" means that the archive has a valid TAM authentication.
+   "tam:none" is expected as output for archives created by borg <1.0.9.
+   "tam:none" could also come from archives created by an attacker.
+   You should verify that "tam:none" archives are authentic and not malicious
+   (== have good content, have correct timestamp, can be extracted successfully).
+   In case you find crappy/malicious archives, you must delete them before proceeding.
+   In low-risk, trusted environments, you may decide on your own risk to skip step 3
+   and just trust in everything being OK.
+
+4. If there are no tam:non archives left at this point, you can skip this step.
+   Run ``borg upgrade --archives-tam <repository>``.
+   This will make sure all archives are TAM authenticated (an archive TAM will be added
+   for all archives still missing one).
+   ``borg check`` would consider TAM-less archives as garbage or a potential attack.
+   Optionally run the same command as in step 3 to see that all archives now are "tam:verified".
+
+
+Vulnerability time line:
+
+* 2023-06-13: Vulnerability discovered during code review by Thomas Waldmann
+* 2023-06-13...: Work on fixing the issue, upgrade procedure, docs.
+* 2023-06-30: CVE was assigned via Github CNA
+* 2023-07-xx: Released fixed version 1.2.5
+
 .. _hashindex_set_bug:
 
 Pre-1.1.11 potential index corruption / data loss issue
@@ -242,6 +308,8 @@ Some things can be recommended for the upgrade process from borg 1.1.x
   take significant time, but after that it will be fast) - for more details
   see below.
 - check the compatibility notes (see below) and adapt your scripts, if needed.
+- borg 1.2.5 has a security fix for the pre-1.2.5 archives spoofing vulnerability
+  (CVE-2023-36811), see details and necessary upgrade procedure described above.
 - if you run into any issues, please check the github issue tracker before
   posting new issues there or elsewhere.
 
@@ -299,14 +367,16 @@ Compatibility notes:
 Change Log
 ==========
 
-Version 1.2.5 (not released yet)
---------------------------------
+Version 1.2.5 (2023-08-30)
+--------------------------
 
 For upgrade and compatibility hints, please also read the section "Upgrade Notes"
 above.
 
 Fixes:
 
+- Security: fix pre-1.2.5 archives spoofing vulnerability (CVE-2023-36811),
+  see details and necessary upgrade procedure described above.
 - create: do not try to read parent dir of recursion root, #7746
 - extract: fix false warning about pattern never matching, #4110
 - diff: remove surrogates before output, #7535

docs/man/borg-benchmark-crud.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-BENCHMARK-CRUD" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-BENCHMARK-CRUD" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-benchmark-crud \- Benchmark Create, Read, Update, Delete for archives.
 .SH SYNOPSIS

docs/man/borg-benchmark.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-BENCHMARK" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-BENCHMARK" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-benchmark \- benchmark command
 .SH SYNOPSIS

docs/man/borg-break-lock.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-BREAK-LOCK" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-BREAK-LOCK" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-break-lock \- Break the repository lock (e.g. in case it was left by a dead borg.
 .SH SYNOPSIS

docs/man/borg-check.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-CHECK" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-CHECK" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-check \- Check repository consistency
 .SH SYNOPSIS

docs/man/borg-common.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-COMMON" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-COMMON" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-common \- Common options of Borg commands
 .SH SYNOPSIS

docs/man/borg-compact.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-COMPACT" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-COMPACT" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-compact \- compact segment files in the repository
 .SH SYNOPSIS

docs/man/borg-compression.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-COMPRESSION" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-COMPRESSION" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-compression \- Details regarding compression
 .SH DESCRIPTION

docs/man/borg-config.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-CONFIG" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-CONFIG" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-config \- get, set, and delete values in a repository or cache config file
 .SH SYNOPSIS

docs/man/borg-create.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-CREATE" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-CREATE" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-create \- Create new archive
 .SH SYNOPSIS

docs/man/borg-delete.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-DELETE" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-DELETE" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-delete \- Delete an existing repository or archives
 .SH SYNOPSIS

docs/man/borg-diff.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-DIFF" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-DIFF" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-diff \- Diff contents of two archives
 .SH SYNOPSIS

docs/man/borg-export-tar.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-EXPORT-TAR" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-EXPORT-TAR" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-export-tar \- Export archive contents as a tarball
 .SH SYNOPSIS

docs/man/borg-extract.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-EXTRACT" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-EXTRACT" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-extract \- Extract archive contents
 .SH SYNOPSIS

docs/man/borg-import-tar.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-IMPORT-TAR" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-IMPORT-TAR" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-import-tar \- Create a backup archive from a tarball
 .SH SYNOPSIS

docs/man/borg-info.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-INFO" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-INFO" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-info \- Show archive details such as disk space used
 .SH SYNOPSIS

docs/man/borg-init.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-INIT" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-INIT" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-init \- Initialize an empty repository
 .SH SYNOPSIS

docs/man/borg-key-change-passphrase.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-KEY-CHANGE-PASSPHRASE" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-KEY-CHANGE-PASSPHRASE" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-key-change-passphrase \- Change repository key file passphrase
 .SH SYNOPSIS

docs/man/borg-key-export.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-KEY-EXPORT" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-KEY-EXPORT" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-key-export \- Export the repository key for backup
 .SH SYNOPSIS

docs/man/borg-key-import.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-KEY-IMPORT" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-KEY-IMPORT" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-key-import \- Import the repository key from backup
 .SH SYNOPSIS

docs/man/borg-key-migrate-to-repokey.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-KEY-MIGRATE-TO-REPOKEY" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-KEY-MIGRATE-TO-REPOKEY" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-key-migrate-to-repokey \- Migrate passphrase -> repokey
 .SH SYNOPSIS

docs/man/borg-key.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-KEY" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-KEY" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-key \- Manage a keyfile or repokey of a repository
 .SH SYNOPSIS

docs/man/borg-list.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-LIST" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-LIST" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-list \- List archive or repository contents
 .SH SYNOPSIS
@@ -217,6 +217,8 @@ bcomment: verbatim archive comment, can contain any character except NUL
 .IP \(bu 2
 id: internal ID of the archive
 .IP \(bu 2
+tam: TAM authentication state of this archive
+.IP \(bu 2
 start: time (start) of creation of the archive
 .IP \(bu 2
 time: alias of \(dqstart\(dq

docs/man/borg-mount.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-MOUNT" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-MOUNT" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-mount \- Mount archive or an entire repository as a FUSE filesystem
 .SH SYNOPSIS

docs/man/borg-patterns.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-PATTERNS" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-PATTERNS" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-patterns \- Details regarding patterns
 .SH DESCRIPTION

docs/man/borg-placeholders.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-PLACEHOLDERS" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-PLACEHOLDERS" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-placeholders \- Details regarding placeholders
 .SH DESCRIPTION

docs/man/borg-prune.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-PRUNE" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-PRUNE" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-prune \- Prune repository archives according to specified rules
 .SH SYNOPSIS

docs/man/borg-recreate.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-RECREATE" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-RECREATE" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-recreate \- Re-create archives
 .SH SYNOPSIS

docs/man/borg-rename.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-RENAME" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-RENAME" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-rename \- Rename an existing archive
 .SH SYNOPSIS

docs/man/borg-serve.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-SERVE" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-SERVE" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-serve \- Start in server mode. This command is usually not used manually.
 .SH SYNOPSIS

docs/man/borg-umount.1

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BORG-UMOUNT" 1 "2023-08-29" "" "borg backup tool"
+.TH "BORG-UMOUNT" 1 "2023-08-30" "" "borg backup tool"
 .SH NAME
 borg-umount \- un-mount the FUSE filesystem
 .SH SYNOPSIS