Discourse is an open-source discussion platform. Welcome banner user name string for logged in users can be vulnerable to XSS attacks, which affect the user themselves or an admin impersonating them. Admins can temporarily alter the welcome_banner.header.logged_in_members site text to remove the preferred_display_name placeholder, or not impersonate
any users for the time being. This vulnerability is fixed in 3.5.0.beta8.
In the Linux kernel, the following vulnerability has been resolved:
mm: fix a UAF when vma->mm is freed after vma->vm_refcnt got dropped
By inducing delays in the right places, Jann Horn created a reproducer for
a hard to hit UAF issue that became possible after VMAs were allowed to be
recycled by adding SLAB_TYPESAFE_BY_RCU to their cache.
Race description is borrowed from Jann's discovery report:
lock_vma_under_rcu() looks up a VMA locklessly with mas_walk() under
rcu_read_lock(). At that point, the VMA may be concurrently freed, and it
can be recycled by another process. vma_start_read() then increments the
vma->vm_refcnt (if it is in an acceptable range), and if this succeeds,
vma_start_read() can return a recycled VMA.
In this scenario where the VMA has been recycled, lock_vma_under_rcu()
will then detect the mismatching ->vm_mm pointer and drop the VMA through
vma_end_read(), which calls vma_refcount_put(). vma_refcount_put() drops
the refcount and then calls rcuwait_wake_up() using a copy of vma->vm_mm.
This is wrong: It implicitly assumes that the caller is keeping the VMA's
mm alive, but in this scenario the caller has no relation to the VMA's mm,
so the rcuwait_wake_up() can cause UAF.
The diagram depicting the race:
T1 T2 T3
== == ==
lock_vma_under_rcu
mas_walk
<VMA gets removed from mm>
mmap
<the same VMA is reallocated>
vma_start_read
__refcount_inc_not_zero_limited_acquire
munmap
__vma_enter_locked
refcount_add_not_zero
vma_end_read
vma_refcount_put
__refcount_dec_and_test
rcuwait_wait_event
<finish operation>
rcuwait_wake_up [UAF]
Note that rcuwait_wait_event() in T3 does not block because refcount was
already dropped by T1. At this point T3 can exit and free the mm causing
UAF in T1.
To avoid this we move vma->vm_mm verification into vma_start_read() and
grab vma->vm_mm to stabilize it before vma_refcount_put() operation.
[surenb@google.com: v3]
In the Linux kernel, the following vulnerability has been resolved:
HID: core: Harden s32ton() against conversion to 0 bits
Testing by the syzbot fuzzer showed that the HID core gets a
shift-out-of-bounds exception when it tries to convert a 32-bit
quantity to a 0-bit quantity. Ideally this should never occur, but
there are buggy devices and some might have a report field with size
set to zero; we shouldn't reject the report or the device just because
of that.
Instead, harden the s32ton() routine so that it returns a reasonable
result instead of crashing when it is called with the number of bits
set to 0 -- the same as what snto32() does.
A security vulnerability has been detected in Scada-LTS 2.7.8.1. This issue affects some unknown processing of the file view_edit.shtm of the component SVG File Handler. Such manipulation of the argument backgroundImageMP leads to cross site scripting. The attack can be launched remotely. The exploit has been disclosed publicly and may be used.
A flaw has been found in Linksys E5600 1.1.0.26. The affected element is the function verify_gemtek_header of the file checkFw.sh of the component Firmware Handler. Executing manipulation can lead to risky cryptographic algorithm. The attack may be launched remotely. The attack requires a high level of complexity. The exploitability is described as difficult. The vendor was contacted early about this disclosure but did not respond in any way.
EzGED3 3.5.0 contains an unauthenticated arbitrary file read vulnerability due to improper access control and insufficient input validation in a script exposed via the web interface. A remote attacker can supply a crafted path parameter to a PHP script to read arbitrary files from the filesystem. The script lacks both authentication checks and secure path handling, allowing directory traversal attacks (e.g., ../../../) to access sensitive files such as configuration files, database dumps, source code, and password reset tokens. If phpMyAdmin is exposed, extracted credentials can be used for direct administrative access. In environments without such tools, attacker-controlled file reads still allow full database extraction by targeting raw MySQL data files. The vendor states that the issue is fixed in 3.5.72.27183.
Incorrect Access Control in the AJAX endpoint functionality in jonkastonka Cookies and Content Security Policy plugin through version 2.29 allows remote attackers to cause a denial of service (database server resource exhaustion) via unlimited database write operations to the wp_ajax_nopriv_cacsp_insert_consent_data endpoint.
A security flaw has been discovered in Scada-LTS 2.7.8.1. This affects an unknown part of the file mailing_lists.shtm. The manipulation of the argument name/userList/address results in cross site scripting. It is possible to launch the attack remotely. The exploit has been released to the public and may be exploited.
A weakness has been identified in Scada-LTS 2.7.8.1. This vulnerability affects unknown code of the file publisher_edit.shtm. This manipulation of the argument Name causes cross site scripting. The attack can be initiated remotely. The exploit has been made available to the public and could be exploited.