[Bug 1957716] Re: Update for CVE-2021-43860 and CVE-2022-21682
@alexmurray, hey, I believe that commit was reverted later as it caused a behavioural regression? The Github advisory (https://github.com/flatpak/flatpak/security/advisories/GHSA-8ch7-5j3h-g4fx) was changed to point to a different commit (https://github.com/flatpak/flatpak/commit/5709f1aaed6579f0136976e14e7f3cae399134ca). When creating that debdiff, if i recall correctly I went though the commits in this branch https://github.com/flatpak/flatpak/commits/flatpak-1.10.x combined with referring to the github advisories and then skipped the "Make --nofilesystem=host/home remove access to subdirs of those" (307ee18dd62f65c1319594501d01bbdb10f88ab8) as it was reverted later with "Revert "Make --nofilesystem=host/home remove access to subdirs of those"" (ed91bba615d4e50ccd7de53ca9861e367175bbfb). Please correct me if you think i've missed something :-) In the github advisory (https://github.com/flatpak/flatpak/security/advisories/GHSA-8ch7-5j3h-g4fx) there are two commits for flatpak-builder so this could also be done. Also note I tried looking at focal/bionic but there are a large amount of merge conflicts due to substantial change in the codebase and I'm not familiar enough with GObject/GLib etc to rewrite that code. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1957716 Title: Update for CVE-2021-43860 and CVE-2022-21682 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/flatpak/+bug/1957716/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1957716] Re: Update for CVE-2021-43860 and CVE-2022-21682
@ahayzen - thanks for the impish debdiff - I was going to sponsor it but I notice you have used a separate set of patches than those linked to by debian and NVD for CVE-2022-21682 - does this also need: https://github.com/flatpak/flatpak/commit/445bddeee657fdc8d2a0a1f0de12975400d4fc1a ? Also does this need an update for flatpak-builder too? Thanks. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1957716 Title: Update for CVE-2021-43860 and CVE-2022-21682 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/flatpak/+bug/1957716/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1957716] Re: Update for CVE-2021-43860 and CVE-2022-21682
** Changed in: flatpak (Ubuntu) Importance: Undecided => Medium ** Changed in: flatpak (Ubuntu Bionic) Importance: Undecided => Medium ** Changed in: flatpak (Ubuntu Focal) Importance: Undecided => Medium ** Changed in: flatpak (Ubuntu Impish) Importance: Undecided => Medium -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1957716 Title: Update for CVE-2021-43860 and CVE-2022-21682 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/flatpak/+bug/1957716/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1957716] Re: Update for CVE-2021-43860 and CVE-2022-21682
Please find attached the debdiff for Ubuntu 21.10 impish. I have performed some testing in a VM and built in a PPA. ** Attachment added: "Impish CVE debdiff" https://bugs.launchpad.net/ubuntu/+source/flatpak/+bug/1957716/+attachment/5557881/+files/flatpak_impish_lp1957716.debdiff.gz -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1957716 Title: Update for CVE-2021-43860 and CVE-2022-21682 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/flatpak/+bug/1957716/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1957716] Re: Update for CVE-2021-43860 and CVE-2022-21682
** Changed in: flatpak (Ubuntu Impish) Status: New => In Progress ** Changed in: flatpak (Ubuntu Impish) Assignee: (unassigned) => Andrew Hayzen (ahayzen) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1957716 Title: Update for CVE-2021-43860 and CVE-2022-21682 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/flatpak/+bug/1957716/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1957716] Re: Update for CVE-2021-43860 and CVE-2022-21682
** Description changed: [Links] https://github.com/flatpak/flatpak/security/advisories/GHSA-qpjc-vq3c-572j ( CVE-2021-43860 ) https://security-tracker.debian.org/tracker/CVE-2021-43860 https://github.com/flatpak/flatpak/security/advisories/GHSA-8ch7-5j3h-g4fx ( CVE-2022-21682 ) https://security-tracker.debian.org/tracker/CVE-2022-21682 [Impact] Versions in Ubuntu right now: Jammy: 1.12.2-2 Impish: 1.10.2-3ubuntu0.1 Focal: 1.6.5-0ubuntu0.4 Bionic: 1.0.9-0ubuntu0.4 Affected versions: all Patched versions: - 1.12.3, 1.10.6 + 1.12.4, 1.10.7 [Test Case] Unknown [Regression Potential] Flatpak has a test suite, which is run on build across all relevant architectures and passes. There is also a manual test plan https://wiki.ubuntu.com/Process/Merges/TestPlan/flatpak . Flatpak has autopkgtests enabled http://autopkgtest.ubuntu.com/packages/f/flatpak . Regression potential is low, and upstream is very responsive to any issues raised. [Patches] The first CVE has 4 patches (+ 1 test patch), the second CVE has 1 patch (+ 6 doc/test patches). [Other Information] For the first advisory with the CVE: Ryan Gonzalez discovered that Flatpak doesn't properly validate that the permissions displayed to the user for an app at install time match the actual permissions granted to the app at runtime, in the case that there's a null byte in the metadata file of an app. Therefore apps can grant themselves permissions without the consent of the user. Flatpak shows permissions to the user during install by reading them from the "xa.metadata" key in the commit metadata. This cannot contain a null terminator, because it is an untrusted GVariant. Flatpak compares these permissions to the actual metadata, from the "metadata" file to ensure it wasn't lied to. However, the actual metadata contents are loaded in several places where they are read as simple C-style strings. That means that, if the metadata file includes a null terminator, only the content of the file from before the terminator gets compared to xa.metadata. Thus, any permissions that appear in the metadata file after a null terminator are applied at runtime but not shown to the user. Maliciously crafted apps can use this to give themselves hidden permissions. In addition, a similar weakness was discovered, where if the permissions in the summary metadata are invalid, they would not be displayed to the user, but the the actual permissions would be granted, even though it didn't match the invalid version. - For the second advisory: flatpak-builder applies finish-args last in the build. At this point the build directory will have the full access that is specified in the manifest, so running flatpak build against it will gain that permissions. Normally this will not be done, so this is not problem. However, if --mirror-screenshots-url is specified, then flatpak-builder will launch flatpak build --nofilesystem=host appstream-utils mirror- screenshots after finalization, which can lead to issues even with the --nofilesystem=host protection. There are two issues: - --nofilesystem=host only overrides the access to the full host. The app can still request access to a specific directory, like --filesystem=~/some-dir, which is not affected by this. - If a filesystem is specified like --filesystem=~/foobar:create, then that directory will be created before running the command. + --nofilesystem=host only overrides the access to the full host. The app can still request access to a specific directory, like --filesystem=~/some-dir, which is not affected by this. + If a filesystem is specified like --filesystem=~/foobar:create, then that directory will be created before running the command. In normal use the only issue is that these empty directories can be created wherever the user has write permissions. However, a malicious application could replace the appstream-util binary and potentially do something more hostile. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1957716 Title: Update for CVE-2021-43860 and CVE-2022-21682 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/flatpak/+bug/1957716/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1957716] Re: Update for CVE-2021-43860 and CVE-2022-21682
** Description changed: [Links] https://github.com/flatpak/flatpak/security/advisories/GHSA-qpjc-vq3c-572j ( CVE-2021-43860 ) https://security-tracker.debian.org/tracker/CVE-2021-43860 https://github.com/flatpak/flatpak/security/advisories/GHSA-8ch7-5j3h-g4fx ( CVE-2022-21682 ) https://security-tracker.debian.org/tracker/CVE-2022-21682 - [Impact] Versions in Ubuntu right now: Jammy: 1.12.2-2 Impish: 1.10.2-3ubuntu0.1 Focal: 1.6.5-0ubuntu0.4 Bionic: 1.0.9-0ubuntu0.4 Affected versions: all Patched versions: 1.12.3, 1.10.6 [Test Case] Unknown [Regression Potential] Flatpak has a test suite, which is run on build across all relevant architectures and passes. There is also a manual test plan https://wiki.ubuntu.com/Process/Merges/TestPlan/flatpak . Flatpak has autopkgtests enabled http://autopkgtest.ubuntu.com/packages/f/flatpak . Regression potential is low, and upstream is very responsive to any issues raised. [Patches] - There are two separate github advisories but only one of them has a CVE. - - The advisory with the CVE has 5 patches, the other has 2 patches. + The first CVE has 4 patches (+ 1 test patch), the second CVE has 1 patch (+ 6 doc/test patches). [Other Information] For the first advisory with the CVE: Ryan Gonzalez discovered that Flatpak doesn't properly validate that the permissions displayed to the user for an app at install time match the actual permissions granted to the app at runtime, in the case that there's a null byte in the metadata file of an app. Therefore apps can grant themselves permissions without the consent of the user. Flatpak shows permissions to the user during install by reading them from the "xa.metadata" key in the commit metadata. This cannot contain a null terminator, because it is an untrusted GVariant. Flatpak compares these permissions to the actual metadata, from the "metadata" file to ensure it wasn't lied to. However, the actual metadata contents are loaded in several places where they are read as simple C-style strings. That means that, if the metadata file includes a null terminator, only the content of the file from before the terminator gets compared to xa.metadata. Thus, any permissions that appear in the metadata file after a null terminator are applied at runtime but not shown to the user. Maliciously crafted apps can use this to give themselves hidden permissions. In addition, a similar weakness was discovered, where if the permissions in the summary metadata are invalid, they would not be displayed to the user, but the the actual permissions would be granted, even though it didn't match the invalid version. + For the second advisory: flatpak-builder applies finish-args last in the build. At this point the build directory will have the full access that is specified in the manifest, so running flatpak build against it will gain that permissions. Normally this will not be done, so this is not problem. However, if --mirror-screenshots-url is specified, then flatpak-builder will launch flatpak build --nofilesystem=host appstream-utils mirror- screenshots after finalization, which can lead to issues even with the --nofilesystem=host protection. - These changes result in a behaviour change as debian have noted in their - changelog: + There are two issues: - * Behaviour changes, as a result of how GHSA-8ch7-5j3h-g4fx was fixed: - - --nofilesystem=host is now special-cased to negate all --filesystem - permissions. Previously, it would cancel out --filesystem=host but - not --filesystem=/some/dir. - - --nofilesystem=home is now special-cased to negate several - home-directory-related filesystem permssions such as - --filesystem=xdg-config/foo, not just --filesystem=host. + --nofilesystem=host only overrides the access to the full host. The app can still request access to a specific directory, like --filesystem=~/some-dir, which is not affected by this. + If a filesystem is specified like --filesystem=~/foobar:create, then that directory will be created before running the command. + + In normal use the only issue is that these empty directories can be + created wherever the user has write permissions. However, a malicious + application could replace the appstream-util binary and potentially do + something more hostile. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1957716 Title: Update for CVE-2021-43860 and CVE-2022-21682 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/flatpak/+bug/1957716/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1957716] Re: Update for CVE-2021-43860 and CVE-2022-21682
Note that Jammy now has 1.12.3-1 so is fixed. ** Summary changed: - Update for CVE-2021-43860 and second github advisory + Update for CVE-2021-43860 and CVE-2022-21682 ** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2022-21682 ** Description changed: [Links] - https://github.com/flatpak/flatpak/security/advisories/GHSA-qpjc-vq3c-572j - https://github.com/flatpak/flatpak/security/advisories/GHSA-8ch7-5j3h-g4fx + https://github.com/flatpak/flatpak/security/advisories/GHSA-qpjc-vq3c-572j ( CVE-2021-43860 ) https://security-tracker.debian.org/tracker/CVE-2021-43860 + + https://github.com/flatpak/flatpak/security/advisories/GHSA-8ch7-5j3h-g4fx ( CVE-2022-21682 ) + https://security-tracker.debian.org/tracker/CVE-2022-21682 + [Impact] Versions in Ubuntu right now: Jammy: 1.12.2-2 Impish: 1.10.2-3ubuntu0.1 Focal: 1.6.5-0ubuntu0.4 Bionic: 1.0.9-0ubuntu0.4 Affected versions: - all + all Patched versions: - 1.12.3, 1.10.6 + 1.12.3, 1.10.6 [Test Case] Unknown [Regression Potential] Flatpak has a test suite, which is run on build across all relevant architectures and passes. There is also a manual test plan https://wiki.ubuntu.com/Process/Merges/TestPlan/flatpak . Flatpak has autopkgtests enabled http://autopkgtest.ubuntu.com/packages/f/flatpak . Regression potential is low, and upstream is very responsive to any issues raised. [Patches] There are two separate github advisories but only one of them has a CVE. The advisory with the CVE has 5 patches, the other has 2 patches. - [Other Information] For the first advisory with the CVE: Ryan Gonzalez discovered that Flatpak doesn't properly validate that the permissions displayed to the user for an app at install time match the actual permissions granted to the app at runtime, in the case that there's a null byte in the metadata file of an app. Therefore apps can grant themselves permissions without the consent of the user. Flatpak shows permissions to the user during install by reading them from the "xa.metadata" key in the commit metadata. This cannot contain a null terminator, because it is an untrusted GVariant. Flatpak compares these permissions to the actual metadata, from the "metadata" file to ensure it wasn't lied to. However, the actual metadata contents are loaded in several places where they are read as simple C-style strings. That means that, if the metadata file includes a null terminator, only the content of the file from before the terminator gets compared to xa.metadata. Thus, any permissions that appear in the metadata file after a null terminator are applied at runtime but not shown to the user. Maliciously crafted apps can use this to give themselves hidden permissions. In addition, a similar weakness was discovered, where if the permissions in the summary metadata are invalid, they would not be displayed to the user, but the the actual permissions would be granted, even though it didn't match the invalid version. - For the second advisory: flatpak-builder applies finish-args last in the build. At this point the build directory will have the full access that is specified in the manifest, so running flatpak build against it will gain that permissions. Normally this will not be done, so this is not problem. However, if --mirror-screenshots-url is specified, then flatpak-builder will launch flatpak build --nofilesystem=host appstream-utils mirror- screenshots after finalization, which can lead to issues even with the --nofilesystem=host protection. - These changes result in a behaviour change as debian have noted in their changelog: - * Behaviour changes, as a result of how GHSA-8ch7-5j3h-g4fx was fixed: - - --nofilesystem=host is now special-cased to negate all --filesystem - permissions. Previously, it would cancel out --filesystem=host but - not --filesystem=/some/dir. - - --nofilesystem=home is now special-cased to negate several - home-directory-related filesystem permssions such as - --filesystem=xdg-config/foo, not just --filesystem=host. + * Behaviour changes, as a result of how GHSA-8ch7-5j3h-g4fx was fixed: + - --nofilesystem=host is now special-cased to negate all --filesystem + permissions. Previously, it would cancel out --filesystem=host but + not --filesystem=/some/dir. + - --nofilesystem=home is now special-cased to negate several + home-directory-related filesystem permssions such as + --filesystem=xdg-config/foo, not just --filesystem=host. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1957716 Title: Update for CVE-2021-43860 and CVE-2022-21682 To manage notifications about this bug go to:
