| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
NFSv4: Fix free of uninitialized nfs4_label on referral lookup.
Send along the already-allocated fattr along with nfs4_fs_locations, and
drop the memcpy of fattr. We end up growing two more allocations, but this
fixes up a crash as:
PID: 790 TASK: ffff88811b43c000 CPU: 0 COMMAND: "ls"
#0 [ffffc90000857920] panic at ffffffff81b9bfde
#1 [ffffc900008579c0] do_trap at ffffffff81023a9b
#2 [ffffc90000857a10] do_error_trap at ffffffff81023b78
#3 [ffffc90000857a58] exc_stack_segment at ffffffff81be1f45
#4 [ffffc90000857a80] asm_exc_stack_segment at ffffffff81c009de
#5 [ffffc90000857b08] nfs_lookup at ffffffffa0302322 [nfs]
#6 [ffffc90000857b70] __lookup_slow at ffffffff813a4a5f
#7 [ffffc90000857c60] walk_component at ffffffff813a86c4
#8 [ffffc90000857cb8] path_lookupat at ffffffff813a9553
#9 [ffffc90000857cf0] filename_lookup at ffffffff813ab86b |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: add accessors to read/set tp->snd_cwnd
We had various bugs over the years with code
breaking the assumption that tp->snd_cwnd is greater
than zero.
Lately, syzbot reported the WARN_ON_ONCE(!tp->prior_cwnd) added
in commit 8b8a321ff72c ("tcp: fix zero cwnd in tcp_cwnd_reduction")
can trigger, and without a repro we would have to spend
considerable time finding the bug.
Instead of complaining too late, we want to catch where
and when tp->snd_cwnd is set to an illegal value. |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix crash when mount with quota enabled
There is a reported crash when mounting ocfs2 with quota enabled.
RIP: 0010:ocfs2_qinfo_lock_res_init+0x44/0x50 [ocfs2]
Call Trace:
ocfs2_local_read_info+0xb9/0x6f0 [ocfs2]
dquot_load_quota_sb+0x216/0x470
dquot_load_quota_inode+0x85/0x100
ocfs2_enable_quotas+0xa0/0x1c0 [ocfs2]
ocfs2_fill_super.cold+0xc8/0x1bf [ocfs2]
mount_bdev+0x185/0x1b0
legacy_get_tree+0x27/0x40
vfs_get_tree+0x25/0xb0
path_mount+0x465/0xac0
__x64_sys_mount+0x103/0x140
It is caused by when initializing dqi_gqlock, the corresponding dqi_type
and dqi_sb are not properly initialized.
This issue is introduced by commit 6c85c2c72819, which wants to avoid
accessing uninitialized variables in error cases. So make global quota
info properly initialized. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nfnetlink_osf: fix possible bogus match in nf_osf_find()
nf_osf_find() incorrectly returns true on mismatch, this leads to
copying uninitialized memory area in nft_osf which can be used to leak
stale kernel stack data to userspace. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_IDLETIMER: fix panic that occurs when timer_type has garbage value
Currently, when the rule related to IDLETIMER is added, idletimer_tg timer
structure is initialized by kmalloc on executing idletimer_tg_create
function. However, in this process timer->timer_type is not defined to
a specific value. Thus, timer->timer_type has garbage value and it occurs
kernel panic. So, this commit fixes the panic by initializing
timer->timer_type using kzalloc instead of kmalloc.
Test commands:
# iptables -A OUTPUT -j IDLETIMER --timeout 1 --label test
$ cat /sys/class/xt_idletimer/timers/test
Killed
Splat looks like:
BUG: KASAN: user-memory-access in alarm_expires_remaining+0x49/0x70
Read of size 8 at addr 0000002e8c7bc4c8 by task cat/917
CPU: 12 PID: 917 Comm: cat Not tainted 5.14.0+ #3 79940a339f71eb14fc81aee1757a20d5bf13eb0e
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
dump_stack_lvl+0x6e/0x9c
kasan_report.cold+0x112/0x117
? alarm_expires_remaining+0x49/0x70
__asan_load8+0x86/0xb0
alarm_expires_remaining+0x49/0x70
idletimer_tg_show+0xe5/0x19b [xt_IDLETIMER 11219304af9316a21bee5ba9d58f76a6b9bccc6d]
dev_attr_show+0x3c/0x60
sysfs_kf_seq_show+0x11d/0x1f0
? device_remove_bin_file+0x20/0x20
kernfs_seq_show+0xa4/0xb0
seq_read_iter+0x29c/0x750
kernfs_fop_read_iter+0x25a/0x2c0
? __fsnotify_parent+0x3d1/0x570
? iov_iter_init+0x70/0x90
new_sync_read+0x2a7/0x3d0
? __x64_sys_llseek+0x230/0x230
? rw_verify_area+0x81/0x150
vfs_read+0x17b/0x240
ksys_read+0xd9/0x180
? vfs_write+0x460/0x460
? do_syscall_64+0x16/0xc0
? lockdep_hardirqs_on+0x79/0x120
__x64_sys_read+0x43/0x50
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f0cdc819142
Code: c0 e9 c2 fe ff ff 50 48 8d 3d 3a ca 0a 00 e8 f5 19 02 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24
RSP: 002b:00007fff28eee5b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f0cdc819142
RDX: 0000000000020000 RSI: 00007f0cdc032000 RDI: 0000000000000003
RBP: 00007f0cdc032000 R08: 00007f0cdc031010 R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: 00005607e9ee31f0
R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000 |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Fix host stage-2 PGD refcount
The KVM page-table library refcounts the pages of concatenated stage-2
PGDs individually. However, when running KVM in protected mode, the
host's stage-2 PGD is currently managed by EL2 as a single high-order
compound page, which can cause the refcount of the tail pages to reach 0
when they shouldn't, hence corrupting the page-table.
Fix this by introducing a new hyp_split_page() helper in the EL2 page
allocator (matching the kernel's split_page() function), and make use of
it from host_s2_zalloc_pages_exact(). |
| In the Linux kernel, the following vulnerability has been resolved:
drm/msm/a4xx: fix error handling in a4xx_gpu_init()
This code returns 1 on error instead of a negative error. It leads to
an Oops in the caller. A second problem is that the check for
"if (ret != -ENODATA)" cannot be true because "ret" is set to 1. |
| In the Linux kernel, the following vulnerability has been resolved:
enetc: Fix illegal access when reading affinity_hint
irq_set_affinity_hit() stores a reference to the cpumask_t
parameter in the irq descriptor, and that reference can be
accessed later from irq_affinity_hint_proc_show(). Since
the cpu_mask parameter passed to irq_set_affinity_hit() has
only temporary storage (it's on the stack memory), later
accesses to it are illegal. Thus reads from the corresponding
procfs affinity_hint file can result in paging request oops.
The issue is fixed by the get_cpu_mask() helper, which provides
a permanent storage for the cpumask_t parameter. |
| In the Linux kernel, the following vulnerability has been resolved:
afs: Fix corruption in reads at fpos 2G-4G from an OpenAFS server
AFS-3 has two data fetch RPC variants, FS.FetchData and FS.FetchData64, and
Linux's afs client switches between them when talking to a non-YFS server
if the read size, the file position or the sum of the two have the upper 32
bits set of the 64-bit value.
This is a problem, however, since the file position and length fields of
FS.FetchData are *signed* 32-bit values.
Fix this by capturing the capability bits obtained from the fileserver when
it's sent an FS.GetCapabilities RPC, rather than just discarding them, and
then picking out the VICED_CAPABILITY_64BITFILES flag. This can then be
used to decide whether to use FS.FetchData or FS.FetchData64 - and also
FS.StoreData or FS.StoreData64 - rather than using upper_32_bits() to
switch on the parameter values.
This capabilities flag could also be used to limit the maximum size of the
file, but all servers must be checked for that.
Note that the issue does not exist with FS.StoreData - that uses *unsigned*
32-bit values. It's also not a problem with Auristor servers as its
YFS.FetchData64 op uses unsigned 64-bit values.
This can be tested by cloning a git repo through an OpenAFS client to an
OpenAFS server and then doing "git status" on it from a Linux afs
client[1]. Provided the clone has a pack file that's in the 2G-4G range,
the git status will show errors like:
error: packfile .git/objects/pack/pack-5e813c51d12b6847bbc0fcd97c2bca66da50079c.pack does not match index
error: packfile .git/objects/pack/pack-5e813c51d12b6847bbc0fcd97c2bca66da50079c.pack does not match index
This can be observed in the server's FileLog with something like the
following appearing:
Sun Aug 29 19:31:39 2021 SRXAFS_FetchData, Fid = 2303380852.491776.3263114, Host 192.168.11.201:7001, Id 1001
Sun Aug 29 19:31:39 2021 CheckRights: len=0, for host=192.168.11.201:7001
Sun Aug 29 19:31:39 2021 FetchData_RXStyle: Pos 18446744071815340032, Len 3154
Sun Aug 29 19:31:39 2021 FetchData_RXStyle: file size 2400758866
...
Sun Aug 29 19:31:40 2021 SRXAFS_FetchData returns 5
Note the file position of 18446744071815340032. This is the requested file
position sign-extended. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/sched: Avoid data corruptions
Wait for all dependencies of a job to complete before
killing it to avoid data corruptions. |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc/bpf: Fix detecting BPF atomic instructions
Commit 91c960b0056672 ("bpf: Rename BPF_XADD and prepare to encode other
atomics in .imm") converted BPF_XADD to BPF_ATOMIC and added a way to
distinguish instructions based on the immediate field. Existing JIT
implementations were updated to check for the immediate field and to
reject programs utilizing anything more than BPF_ADD (such as BPF_FETCH)
in the immediate field.
However, the check added to powerpc64 JIT did not look at the correct
BPF instruction. Due to this, such programs would be accepted and
incorrectly JIT'ed resulting in soft lockups, as seen with the atomic
bounds test. Fix this by looking at the correct immediate value. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: PPC: Fix kvm_arch_vcpu_ioctl vcpu_load leak
vcpu_put is not called if the user copy fails. This can result in preempt
notifier corruption and crashes, among other issues. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: target: core: Avoid smp_processor_id() in preemptible code
The BUG message "BUG: using smp_processor_id() in preemptible [00000000]
code" was observed for TCMU devices with kernel config DEBUG_PREEMPT.
The message was observed when blktests block/005 was run on TCMU devices
with fileio backend or user:zbc backend [1]. The commit 1130b499b4a7
("scsi: target: tcm_loop: Use LIO wq cmd submission helper") triggered the
symptom. The commit modified work queue to handle commands and changed
'current->nr_cpu_allowed' at smp_processor_id() call.
The message was also observed at system shutdown when TCMU devices were not
cleaned up [2]. The function smp_processor_id() was called in SCSI host
work queue for abort handling, and triggered the BUG message. This symptom
was observed regardless of the commit 1130b499b4a7 ("scsi: target:
tcm_loop: Use LIO wq cmd submission helper").
To avoid the preemptible code check at smp_processor_id(), get CPU ID with
raw_smp_processor_id() instead. The CPU ID is used for performance
improvement then thread move to other CPU will not affect the code.
[1]
[ 56.468103] run blktests block/005 at 2021-05-12 14:16:38
[ 57.369473] check_preemption_disabled: 85 callbacks suppressed
[ 57.369480] BUG: using smp_processor_id() in preemptible [00000000] code: fio/1511
[ 57.369506] BUG: using smp_processor_id() in preemptible [00000000] code: fio/1510
[ 57.369512] BUG: using smp_processor_id() in preemptible [00000000] code: fio/1506
[ 57.369552] caller is __target_init_cmd+0x157/0x170 [target_core_mod]
[ 57.369606] CPU: 4 PID: 1506 Comm: fio Not tainted 5.13.0-rc1+ #34
[ 57.369613] Hardware name: System manufacturer System Product Name/PRIME Z270-A, BIOS 1302 03/15/2018
[ 57.369617] Call Trace:
[ 57.369621] BUG: using smp_processor_id() in preemptible [00000000] code: fio/1507
[ 57.369628] dump_stack+0x6d/0x89
[ 57.369642] check_preemption_disabled+0xc8/0xd0
[ 57.369628] caller is __target_init_cmd+0x157/0x170 [target_core_mod]
[ 57.369655] __target_init_cmd+0x157/0x170 [target_core_mod]
[ 57.369695] target_init_cmd+0x76/0x90 [target_core_mod]
[ 57.369732] tcm_loop_queuecommand+0x109/0x210 [tcm_loop]
[ 57.369744] scsi_queue_rq+0x38e/0xc40
[ 57.369761] __blk_mq_try_issue_directly+0x109/0x1c0
[ 57.369779] blk_mq_try_issue_directly+0x43/0x90
[ 57.369790] blk_mq_submit_bio+0x4e5/0x5d0
[ 57.369812] submit_bio_noacct+0x46e/0x4e0
[ 57.369830] __blkdev_direct_IO_simple+0x1a3/0x2d0
[ 57.369859] ? set_init_blocksize.isra.0+0x60/0x60
[ 57.369880] generic_file_read_iter+0x89/0x160
[ 57.369898] blkdev_read_iter+0x44/0x60
[ 57.369906] new_sync_read+0x102/0x170
[ 57.369929] vfs_read+0xd4/0x160
[ 57.369941] __x64_sys_pread64+0x6e/0xa0
[ 57.369946] ? lockdep_hardirqs_on+0x79/0x100
[ 57.369958] do_syscall_64+0x3a/0x70
[ 57.369965] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 57.369973] RIP: 0033:0x7f7ed4c1399f
[ 57.369979] Code: 08 89 3c 24 48 89 4c 24 18 e8 7d f3 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 48 8b 74 24 08 8b 3c 24 b8 11 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 04 24 e8 cd f3 ff ff 48 8b
[ 57.369983] RSP: 002b:00007ffd7918c580 EFLAGS: 00000293 ORIG_RAX: 0000000000000011
[ 57.369990] RAX: ffffffffffffffda RBX: 00000000015b4540 RCX: 00007f7ed4c1399f
[ 57.369993] RDX: 0000000000001000 RSI: 00000000015de000 RDI: 0000000000000009
[ 57.369996] RBP: 00000000015b4540 R08: 0000000000000000 R09: 0000000000000001
[ 57.369999] R10: 0000000000e5c000 R11: 0000000000000293 R12: 00007f7eb5269a70
[ 57.370002] R13: 0000000000000000 R14: 0000000000001000 R15: 00000000015b4568
[ 57.370031] CPU: 7 PID: 1507 Comm: fio Not tainted 5.13.0-rc1+ #34
[ 57.370036] Hardware name: System manufacturer System Product Name/PRIME Z270-A, BIOS 1302 03/15/2018
[ 57.370039] Call Trace:
[ 57.370045] dump_stack+0x6d/0x89
[ 57.370056] ch
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
NFS: fix an incorrect limit in filelayout_decode_layout()
The "sizeof(struct nfs_fh)" is two bytes too large and could lead to
memory corruption. It should be NFS_MAXFHSIZE because that's the size
of the ->data[] buffer.
I reversed the size of the arguments to put the variable on the left. |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: wait and exit until all work queues are done
On some host, a crash could be triggered simply by repeating these
commands several times:
# modprobe tipc
# tipc bearer enable media udp name UDP1 localip 127.0.0.1
# rmmod tipc
[] BUG: unable to handle kernel paging request at ffffffffc096bb00
[] Workqueue: events 0xffffffffc096bb00
[] Call Trace:
[] ? process_one_work+0x1a7/0x360
[] ? worker_thread+0x30/0x390
[] ? create_worker+0x1a0/0x1a0
[] ? kthread+0x116/0x130
[] ? kthread_flush_work_fn+0x10/0x10
[] ? ret_from_fork+0x35/0x40
When removing the TIPC module, the UDP tunnel sock will be delayed to
release in a work queue as sock_release() can't be done in rtnl_lock().
If the work queue is schedule to run after the TIPC module is removed,
kernel will crash as the work queue function cleanup_beareri() code no
longer exists when trying to invoke it.
To fix it, this patch introduce a member wq_count in tipc_net to track
the numbers of work queues in schedule, and wait and exit until all
work queues are done in tipc_exit_net(). |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: fix data stream corruption
Maxim reported several issues when forcing a TCP transparent proxy
to use the MPTCP protocol for the inbound connections. He also
provided a clean reproducer.
The problem boils down to 'mptcp_frag_can_collapse_to()' assuming
that only MPTCP will use the given page_frag.
If others - e.g. the plain TCP protocol - allocate page fragments,
we can end-up re-using already allocated memory for mptcp_data_frag.
Fix the issue ensuring that the to-be-expanded data fragment is
located at the current page frag end.
v1 -> v2:
- added missing fixes tag (Mat) |
| In the Linux kernel, the following vulnerability has been resolved:
net: lantiq: fix memory corruption in RX ring
In a situation where memory allocation or dma mapping fails, an
invalid address is programmed into the descriptor. This can lead
to memory corruption. If the memory allocation fails, DMA should
reuse the previous skb and mapping and drop the packet. This patch
also increments rx drop counter. |
| In the Linux kernel, the following vulnerability has been resolved:
net: zero-initialize tc skb extension on allocation
Function skb_ext_add() doesn't initialize created skb extension with any
value and leaves it up to the user. However, since extension of type
TC_SKB_EXT originally contained only single value tc_skb_ext->chain its
users used to just assign the chain value without setting whole extension
memory to zero first. This assumption changed when TC_SKB_EXT extension was
extended with additional fields but not all users were updated to
initialize the new fields which leads to use of uninitialized memory
afterwards. UBSAN log:
[ 778.299821] UBSAN: invalid-load in net/openvswitch/flow.c:899:28
[ 778.301495] load of value 107 is not a valid value for type '_Bool'
[ 778.303215] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc7+ #2
[ 778.304933] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 778.307901] Call Trace:
[ 778.308680] <IRQ>
[ 778.309358] dump_stack+0xbb/0x107
[ 778.310307] ubsan_epilogue+0x5/0x40
[ 778.311167] __ubsan_handle_load_invalid_value.cold+0x43/0x48
[ 778.312454] ? memset+0x20/0x40
[ 778.313230] ovs_flow_key_extract.cold+0xf/0x14 [openvswitch]
[ 778.314532] ovs_vport_receive+0x19e/0x2e0 [openvswitch]
[ 778.315749] ? ovs_vport_find_upcall_portid+0x330/0x330 [openvswitch]
[ 778.317188] ? create_prof_cpu_mask+0x20/0x20
[ 778.318220] ? arch_stack_walk+0x82/0xf0
[ 778.319153] ? secondary_startup_64_no_verify+0xb0/0xbb
[ 778.320399] ? stack_trace_save+0x91/0xc0
[ 778.321362] ? stack_trace_consume_entry+0x160/0x160
[ 778.322517] ? lock_release+0x52e/0x760
[ 778.323444] netdev_frame_hook+0x323/0x610 [openvswitch]
[ 778.324668] ? ovs_netdev_get_vport+0xe0/0xe0 [openvswitch]
[ 778.325950] __netif_receive_skb_core+0x771/0x2db0
[ 778.327067] ? lock_downgrade+0x6e0/0x6f0
[ 778.328021] ? lock_acquire+0x565/0x720
[ 778.328940] ? generic_xdp_tx+0x4f0/0x4f0
[ 778.329902] ? inet_gro_receive+0x2a7/0x10a0
[ 778.330914] ? lock_downgrade+0x6f0/0x6f0
[ 778.331867] ? udp4_gro_receive+0x4c4/0x13e0
[ 778.332876] ? lock_release+0x52e/0x760
[ 778.333808] ? dev_gro_receive+0xcc8/0x2380
[ 778.334810] ? lock_downgrade+0x6f0/0x6f0
[ 778.335769] __netif_receive_skb_list_core+0x295/0x820
[ 778.336955] ? process_backlog+0x780/0x780
[ 778.337941] ? mlx5e_rep_tc_netdevice_event_unregister+0x20/0x20 [mlx5_core]
[ 778.339613] ? seqcount_lockdep_reader_access.constprop.0+0xa7/0xc0
[ 778.341033] ? kvm_clock_get_cycles+0x14/0x20
[ 778.342072] netif_receive_skb_list_internal+0x5f5/0xcb0
[ 778.343288] ? __kasan_kmalloc+0x7a/0x90
[ 778.344234] ? mlx5e_handle_rx_cqe_mpwrq+0x9e0/0x9e0 [mlx5_core]
[ 778.345676] ? mlx5e_xmit_xdp_frame_mpwqe+0x14d0/0x14d0 [mlx5_core]
[ 778.347140] ? __netif_receive_skb_list_core+0x820/0x820
[ 778.348351] ? mlx5e_post_rx_mpwqes+0xa6/0x25d0 [mlx5_core]
[ 778.349688] ? napi_gro_flush+0x26c/0x3c0
[ 778.350641] napi_complete_done+0x188/0x6b0
[ 778.351627] mlx5e_napi_poll+0x373/0x1b80 [mlx5_core]
[ 778.352853] __napi_poll+0x9f/0x510
[ 778.353704] ? mlx5_flow_namespace_set_mode+0x260/0x260 [mlx5_core]
[ 778.355158] net_rx_action+0x34c/0xa40
[ 778.356060] ? napi_threaded_poll+0x3d0/0x3d0
[ 778.357083] ? sched_clock_cpu+0x18/0x190
[ 778.358041] ? __common_interrupt+0x8e/0x1a0
[ 778.359045] __do_softirq+0x1ce/0x984
[ 778.359938] __irq_exit_rcu+0x137/0x1d0
[ 778.360865] irq_exit_rcu+0xa/0x20
[ 778.361708] common_interrupt+0x80/0xa0
[ 778.362640] </IRQ>
[ 778.363212] asm_common_interrupt+0x1e/0x40
[ 778.364204] RIP: 0010:native_safe_halt+0xe/0x10
[ 778.365273] Code: 4f ff ff ff 4c 89 e7 e8 50 3f 40 fe e9 dc fe ff ff 48 89 df e8 43 3f 40 fe eb 90 cc e9 07 00 00 00 0f 00 2d 74 05 62 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d 64 05 62 00 f4 c3 cc cc 0f 1f 44 00
[ 778.369355] RSP: 0018:ffffffff84407e48 EFLAGS: 00000246
[ 778.370570] RAX
---truncated--- |
| A vulnerability in the Xerte Online Tools allows for RCE through the antivirus binary path in the tools server settings, which can be changed to a PHP interpreter, allowing an attacker to upload PHP data that will then be executed. |
| The Kirki WordPress plugin before 6.0.12 does not validate a user-supplied URL before requesting it server-side, allowing unauthenticated attackers to make the site issue HTTP requests to arbitrary hosts (Server-Side Request Forgery). |