Debian: Security Vulnerabilities
Flatpak is a Linux application sandboxing and distribution framework. Prior to versions 1.14.0 and 1.15.10, a malicious or compromised Flatpak app using persistent directories could access and write files outside of what it would otherwise have access to, which is an attack on integrity and confidentiality.
When `persistent=subdir` is used in the application permissions (represented as `--persist=subdir` in the command-line interface), that means that an application which otherwise doesn't have access to the real user home directory will see an empty home directory with a writeable subdirectory `subdir`. Behind the scenes, this directory is actually a bind mount and the data is stored in the per-application directory as `~/.var/app/$APPID/subdir`. This allows existing apps that are not aware of the per-application directory to still work as intended without general home directory access.
However, the application does have write access to the application directory `~/.var/app/$APPID` where this directory is stored. If the source directory for the `persistent`/`--persist` option is replaced by a symlink, then the next time the application is started, the bind mount will follow the symlink and mount whatever it points to into the sandbox.
Partial protection against this vulnerability can be provided by patching Flatpak using the patches in commits ceec2ffc and 98f79773. However, this leaves a race condition that could be exploited by two instances of a malicious app running in parallel. Closing the race condition requires updating or patching the version of bubblewrap that is used by Flatpak to add the new `--bind-fd` option using the patch and then patching Flatpak to use it. If Flatpak has been configured at build-time with `-Dsystem_bubblewrap=bwrap` (1.15.x) or `--with-system-bubblewrap=bwrap` (1.14.x or older), or a similar option, then the version of bubblewrap that needs to be patched is a system copy that is distributed separately, typically `/usr/bin/bwrap`. This configuration is the one that is typically used in Linux distributions. If Flatpak has been configured at build-time with `-Dsystem_bubblewrap=` (1.15.x) or with `--without-system-bubblewrap` (1.14.x or older), then it is the bundled version of bubblewrap that is included with Flatpak that must be patched. This is typically installed as `/usr/libexec/flatpak-bwrap`. This configuration is the default when building from source code.
For the 1.14.x stable branch, these changes are included in Flatpak 1.14.10. The bundled version of bubblewrap included in this release has been updated to 0.6.3. For the 1.15.x development branch, these changes are included in Flatpak 1.15.10. The bundled version of bubblewrap in this release is a Meson "wrap" subproject, which has been updated to 0.10.0. The 1.12.x and 1.10.x branches will not be updated for this vulnerability. Long-term support OS distributions should backport the individual changes into their versions of Flatpak and bubblewrap, or update to newer versions if their stability policy allows it. As a workaround, avoid using applications using the `persistent` (`--persist`) permission.
CVSS Score
10.0
EPSS Score
0.065
Published
2024-08-15
Attackers can craft a malicious prompt that coerces the language model into executing arbitrary JavaScript in the context of the web page.
CVSS Score
6.1
EPSS Score
0.002
Published
2024-08-07
Attacker controlled files can be uploaded to arbitrary locations on the web server's filesystem by abusing a path traversal vulnerability.
CVSS Score
8.8
EPSS Score
0.002
Published
2024-08-07
In the Linux kernel, the following vulnerability has been resolved:
nvme: avoid double free special payload
If a discard request needs to be retried, and that retry may fail before
a new special payload is added, a double free will result. Clear the
RQF_SPECIAL_LOAD when the request is cleaned.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
block/ioctl: prefer different overflow check
Running syzkaller with the newly reintroduced signed integer overflow
sanitizer shows this report:
[ 62.982337] ------------[ cut here ]------------
[ 62.985692] cgroup: Invalid name
[ 62.986211] UBSAN: signed-integer-overflow in ../block/ioctl.c:36:46
[ 62.989370] 9pnet_fd: p9_fd_create_tcp (7343): problem connecting socket to 127.0.0.1
[ 62.992992] 9223372036854775807 + 4095 cannot be represented in type 'long long'
[ 62.997827] 9pnet_fd: p9_fd_create_tcp (7345): problem connecting socket to 127.0.0.1
[ 62.999369] random: crng reseeded on system resumption
[ 63.000634] GUP no longer grows the stack in syz-executor.2 (7353): 20002000-20003000 (20001000)
[ 63.000668] CPU: 0 PID: 7353 Comm: syz-executor.2 Not tainted 6.8.0-rc2-00035-gb3ef86b5a957 #1
[ 63.000677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 63.000682] Call Trace:
[ 63.000686] <TASK>
[ 63.000731] dump_stack_lvl+0x93/0xd0
[ 63.000919] __get_user_pages+0x903/0xd30
[ 63.001030] __gup_longterm_locked+0x153e/0x1ba0
[ 63.001041] ? _raw_read_unlock_irqrestore+0x17/0x50
[ 63.001072] ? try_get_folio+0x29c/0x2d0
[ 63.001083] internal_get_user_pages_fast+0x1119/0x1530
[ 63.001109] iov_iter_extract_pages+0x23b/0x580
[ 63.001206] bio_iov_iter_get_pages+0x4de/0x1220
[ 63.001235] iomap_dio_bio_iter+0x9b6/0x1410
[ 63.001297] __iomap_dio_rw+0xab4/0x1810
[ 63.001316] iomap_dio_rw+0x45/0xa0
[ 63.001328] ext4_file_write_iter+0xdde/0x1390
[ 63.001372] vfs_write+0x599/0xbd0
[ 63.001394] ksys_write+0xc8/0x190
[ 63.001403] do_syscall_64+0xd4/0x1b0
[ 63.001421] ? arch_exit_to_user_mode_prepare+0x3a/0x60
[ 63.001479] entry_SYSCALL_64_after_hwframe+0x6f/0x77
[ 63.001535] RIP: 0033:0x7f7fd3ebf539
[ 63.001551] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
[ 63.001562] RSP: 002b:00007f7fd32570c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 63.001584] RAX: ffffffffffffffda RBX: 00007f7fd3ff3f80 RCX: 00007f7fd3ebf539
[ 63.001590] RDX: 4db6d1e4f7e43360 RSI: 0000000020000000 RDI: 0000000000000004
[ 63.001595] RBP: 00007f7fd3f1e496 R08: 0000000000000000 R09: 0000000000000000
[ 63.001599] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[ 63.001604] R13: 0000000000000006 R14: 00007f7fd3ff3f80 R15: 00007ffd415ad2b8
...
[ 63.018142] ---[ end trace ]---
Historically, the signed integer overflow sanitizer did not work in the
kernel due to its interaction with `-fwrapv` but this has since been
changed [1] in the newest version of Clang; It was re-enabled in the
kernel with Commit 557f8c582a9ba8ab ("ubsan: Reintroduce signed overflow
sanitizer").
Let's rework this overflow checking logic to not actually perform an
overflow during the check itself, thus avoiding the UBSAN splat.
[1]: https://github.com/llvm/llvm-project/pull/82432
CVSS Score
7.8
EPSS Score
0.0
Published
2024-07-12
In the Linux kernel, the following vulnerability has been resolved:
ima: Fix use-after-free on a dentry's dname.name
->d_name.name can change on rename and the earlier value can be freed;
there are conditions sufficient to stabilize it (->d_lock on dentry,
->d_lock on its parent, ->i_rwsem exclusive on the parent's inode,
rename_lock), but none of those are met at any of the sites. Take a stable
snapshot of the name instead.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-07-12
In the Linux kernel, the following vulnerability has been resolved:
btrfs: zoned: fix use-after-free due to race with dev replace
While loading a zone's info during creation of a block group, we can race
with a device replace operation and then trigger a use-after-free on the
device that was just replaced (source device of the replace operation).
This happens because at btrfs_load_zone_info() we extract a device from
the chunk map into a local variable and then use the device while not
under the protection of the device replace rwsem. So if there's a device
replace operation happening when we extract the device and that device
is the source of the replace operation, we will trigger a use-after-free
if before we finish using the device the replace operation finishes and
frees the device.
Fix this by enlarging the critical section under the protection of the
device replace rwsem so that all uses of the device are done inside the
critical section.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-07-12
A security regression (CVE-2006-5051) was discovered in OpenSSH's server (sshd). There is a race condition which can lead sshd to handle some signals in an unsafe manner. An unauthenticated, remote attacker may be able to trigger it by failing to authenticate within a set time period.
CVSS Score
8.1
EPSS Score
0.508
Published
2024-07-01
In MIT Kerberos 5 (aka krb5) before 1.21.3, an attacker can cause invalid memory reads during GSS message token handling by sending message tokens with invalid length fields.
CVSS Score
9.1
EPSS Score
0.026
Published
2024-06-28
In the Linux kernel, the following vulnerability has been resolved:
ftrace: Fix possible use-after-free issue in ftrace_location()
KASAN reports a bug:
BUG: KASAN: use-after-free in ftrace_location+0x90/0x120
Read of size 8 at addr ffff888141d40010 by task insmod/424
CPU: 8 PID: 424 Comm: insmod Tainted: G W 6.9.0-rc2+
[...]
Call Trace:
<TASK>
dump_stack_lvl+0x68/0xa0
print_report+0xcf/0x610
kasan_report+0xb5/0xe0
ftrace_location+0x90/0x120
register_kprobe+0x14b/0xa40
kprobe_init+0x2d/0xff0 [kprobe_example]
do_one_initcall+0x8f/0x2d0
do_init_module+0x13a/0x3c0
load_module+0x3082/0x33d0
init_module_from_file+0xd2/0x130
__x64_sys_finit_module+0x306/0x440
do_syscall_64+0x68/0x140
entry_SYSCALL_64_after_hwframe+0x71/0x79
The root cause is that, in lookup_rec(), ftrace record of some address
is being searched in ftrace pages of some module, but those ftrace pages
at the same time is being freed in ftrace_release_mod() as the
corresponding module is being deleted:
CPU1 | CPU2
register_kprobes() { | delete_module() {
check_kprobe_address_safe() { |
arch_check_ftrace_location() { |
ftrace_location() { |
lookup_rec() // USE! | ftrace_release_mod() // Free!
To fix this issue:
1. Hold rcu lock as accessing ftrace pages in ftrace_location_range();
2. Use ftrace_location_range() instead of lookup_rec() in
ftrace_location();
3. Call synchronize_rcu() before freeing any ftrace pages both in
ftrace_process_locs()/ftrace_release_mod()/ftrace_free_mem().
CVSS Score
7.8
EPSS Score
0.0
Published
2024-06-19