Issue summary: An OpenSSL TLS 1.3 server may fail to negotiate the expected
preferred key exchange group when its key exchange group configuration includes
the default by using the 'DEFAULT' keyword.
Impact summary: A less preferred key exchange may be used even when a more
preferred group is supported by both client and server, if the group
was not included among the client's initial predicated keyshares.
This will sometimes be the case with the new hybrid post-quantum groups,
if the client chooses to defer their use until specifically requested by
the server.
If an OpenSSL TLS 1.3 server's configuration uses the 'DEFAULT' keyword to
interpolate the built-in default group list into its own configuration, perhaps
adding or removing specific elements, then an implementation defect causes the
'DEFAULT' list to lose its 'tuple' structure, and all server-supported groups
were treated as a single sufficiently secure 'tuple', with the server not
sending a Hello Retry Request (HRR) even when a group in a more preferred tuple
was mutually supported.
As a result, the client and server might fail to negotiate a mutually supported
post-quantum key agreement group, such as 'X25519MLKEM768', if the client's
configuration results in only 'classical' groups (such as 'X25519' being the
only ones in the client's initial keyshare prediction).
OpenSSL 3.5 and later support a new syntax for selecting the most preferred TLS
1.3 key agreement group on TLS servers. The old syntax had a single 'flat'
list of groups, and treated all the supported groups as sufficiently secure.
If any of the keyshares predicted by the client were supported by the server
the most preferred among these was selected, even if other groups supported by
the client, but not included in the list of predicted keyshares would have been
more preferred, if included.
The new syntax partitions the groups into distinct 'tuples' of roughly
equivalent security. Within each tuple the most preferred group included among
the client's predicted keyshares is chosen, but if the client supports a group
from a more preferred tuple, but did not predict any corresponding keyshares,
the server will ask the client to retry the ClientHello (by issuing a Hello
Retry Request or HRR) with the most preferred mutually supported group.
The above works as expected when the server's configuration uses the built-in
default group list, or explicitly defines its own list by directly defining the
various desired groups and group 'tuples'.
No OpenSSL FIPS modules are affected by this issue, the code in question lies
outside the FIPS boundary.
OpenSSL 3.6 and 3.5 are vulnerable to this issue.
OpenSSL 3.6 users should upgrade to OpenSSL 3.6.2 once it is released.
OpenSSL 3.5 users should upgrade to OpenSSL 3.5.6 once it is released.
OpenSSL 3.4, 3.3, 3.0, 1.0.2 and 1.1.1 are not affected by this issue.
A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected application do not properly validate input parameters in its REST API, resulting in improper handling of unexpected arguments.
This could allow an authenticated attacker to execute arbitrary code with limited privileges.
A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected device stores sensitive information in the firmware. This could allow an attacker to access and misuse this information, potentially impacting the device’s confidentiality, integrity, and availability.
A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected device contains a USB port which allows unauthenticated connections. This could allow an attacker with physical access to the device to trigger reboot that could cause denial of service condition.
A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected application exhibits inconsistent SNMP behavior, such as unexpected service availability and unreliable configuration handling across protocol versions. This could allow an attacker to access sensitive data, potentially leading to a breach of confidentiality.
A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected devices exposes server information in its responses.
This could allow an attacker with network access to gain useful information, increasing the likelihood of targeted attacks.
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix oob access in cgroup local storage
Lonial reported that an out-of-bounds access in cgroup local storage
can be crafted via tail calls. Given two programs each utilizing a
cgroup local storage with a different value size, and one program
doing a tail call into the other. The verifier will validate each of
the indivial programs just fine. However, in the runtime context
the bpf_cg_run_ctx holds an bpf_prog_array_item which contains the
BPF program as well as any cgroup local storage flavor the program
uses. Helpers such as bpf_get_local_storage() pick this up from the
runtime context:
ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
storage = ctx->prog_item->cgroup_storage[stype];
if (stype == BPF_CGROUP_STORAGE_SHARED)
ptr = &READ_ONCE(storage->buf)->data[0];
else
ptr = this_cpu_ptr(storage->percpu_buf);
For the second program which was called from the originally attached
one, this means bpf_get_local_storage() will pick up the former
program's map, not its own. With mismatching sizes, this can result
in an unintended out-of-bounds access.
To fix this issue, we need to extend bpf_map_owner with an array of
storage_cookie[] to match on i) the exact maps from the original
program if the second program was using bpf_get_local_storage(), or
ii) allow the tail call combination if the second program was not
using any of the cgroup local storage maps.