| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| Issue summary: Calling the OpenSSL API function SSL_select_next_proto with an
empty supported client protocols buffer may cause a crash or memory contents to
be sent to the peer.
Impact summary: A buffer overread can have a range of potential consequences
such as unexpected application beahviour or a crash. In particular this issue
could result in up to 255 bytes of arbitrary private data from memory being sent
to the peer leading to a loss of confidentiality. However, only applications
that directly call the SSL_select_next_proto function with a 0 length list of
supported client protocols are affected by this issue. This would normally never
be a valid scenario and is typically not under attacker control but may occur by
accident in the case of a configuration or programming error in the calling
application.
The OpenSSL API function SSL_select_next_proto is typically used by TLS
applications that support ALPN (Application Layer Protocol Negotiation) or NPN
(Next Protocol Negotiation). NPN is older, was never standardised and
is deprecated in favour of ALPN. We believe that ALPN is significantly more
widely deployed than NPN. The SSL_select_next_proto function accepts a list of
protocols from the server and a list of protocols from the client and returns
the first protocol that appears in the server list that also appears in the
client list. In the case of no overlap between the two lists it returns the
first item in the client list. In either case it will signal whether an overlap
between the two lists was found. In the case where SSL_select_next_proto is
called with a zero length client list it fails to notice this condition and
returns the memory immediately following the client list pointer (and reports
that there was no overlap in the lists).
This function is typically called from a server side application callback for
ALPN or a client side application callback for NPN. In the case of ALPN the list
of protocols supplied by the client is guaranteed by libssl to never be zero in
length. The list of server protocols comes from the application and should never
normally be expected to be of zero length. In this case if the
SSL_select_next_proto function has been called as expected (with the list
supplied by the client passed in the client/client_len parameters), then the
application will not be vulnerable to this issue. If the application has
accidentally been configured with a zero length server list, and has
accidentally passed that zero length server list in the client/client_len
parameters, and has additionally failed to correctly handle a "no overlap"
response (which would normally result in a handshake failure in ALPN) then it
will be vulnerable to this problem.
In the case of NPN, the protocol permits the client to opportunistically select
a protocol when there is no overlap. OpenSSL returns the first client protocol
in the no overlap case in support of this. The list of client protocols comes
from the application and should never normally be expected to be of zero length.
However if the SSL_select_next_proto function is accidentally called with a
client_len of 0 then an invalid memory pointer will be returned instead. If the
application uses this output as the opportunistic protocol then the loss of
confidentiality will occur.
This issue has been assessed as Low severity because applications are most
likely to be vulnerable if they are using NPN instead of ALPN - but NPN is not
widely used. It also requires an application configuration or programming error.
Finally, this issue would not typically be under attacker control making active
exploitation unlikely.
The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue.
Due to the low severity of this issue we are not issuing new releases of
OpenSSL at this time. The fix will be included in the next releases when they
become available. |
| libexpat through 2.6.1 allows an XML Entity Expansion attack when there is isolated use of external parsers (created via XML_ExternalEntityParserCreate). |
| An out-of-memory flaw was found in libtiff that could be triggered by passing a crafted tiff file to the TIFFRasterScanlineSize64() API. This flaw allows a remote attacker to cause a denial of service via a crafted input with a size smaller than 379 KB. |
| Memory Corruption via Uncanceled AIO Requests on Error: libkcapi's one-shot AIO path can return an error before all submitted IOCBs are drained, allowing later kernel writes into caller-owned output buffers. |
| A flaw was found in GDB's STABS debug format parser. The
read_member_functions() function in gdb/stabsread.c contains a linked
list removal bug in the code that separates destructor and non-destructor
member functions of C++ classes. The bug causes the destructor entries to
remain in the main function list while the list length counter is
decremented, resulting in an out-of-bounds write when the function list
is copied to its final allocated array. An attacker can craft an ELF
binary with malicious .stab and .stabstr sections that triggers this
out-of-bounds write when a user opens the file in GDB and performs any
symbol-inspection operation such as setting a breakpoint. The inferior
process does not need to be executed. Under controlled conditions, this
was demonstrated to achieve execution of arbitrary commands within the
GDB process. |
| A flaw has been discovered in GnuTLS where an application crash can be induced when attempting to verify a specially crafted .pem bundle using the "certtool --verify-chain" command. |
| A flaw was found in GnuTLS. The Minerva attack is a cryptographic vulnerability that exploits deterministic behavior in systems like GnuTLS, leading to side-channel leaks. In specific scenarios, such as when using the GNUTLS_PRIVKEY_FLAG_REPRODUCIBLE flag, it can result in a noticeable step in nonce size from 513 to 512 bits, exposing a potential timing side-channel. |
| A use-after-free flaw was found in the Linux kernel’s Netfilter functionality when adding a rule with NFTA_RULE_CHAIN_ID. This flaw allows a local user to crash or escalate their privileges on the system. |
| A vulnerability was found in FreeIPA in how the initial implementation of MS-SFU by MIT Kerberos was missing a condition for granting the "forwardable" flag on S4U2Self tickets. Fixing this mistake required adding a special case for the check_allowed_to_delegate() function: If the target service argument is NULL, then it means the KDC is probing for general constrained delegation rules and not checking a specific S4U2Proxy request.
In FreeIPA 4.11.0, the behavior of ipadb_match_acl() was modified to match the changes from upstream MIT Kerberos 1.20. However, a mistake resulting in this mechanism applies in cases where the target service argument is set AND where it is unset. This results in S4U2Proxy requests being accepted regardless of whether or not there is a matching service delegation rule. |
| A use-after-free vulnerability was found in drivers/nvme/target/tcp.c` in `nvmet_tcp_free_crypto` due to a logical bug in the NVMe/TCP subsystem in the Linux kernel. This issue may allow a malicious user to cause a use-after-free and double-free problem, which may permit remote code execution or lead to local privilege escalation. |
| A vulnerability was found in MariaDB. An OpenVAS port scan on ports 3306 and 4567 allows a malicious remote client to cause a denial of service. |
| A flaw was found in pfn_swap_entry_to_page in memory management subsystem in the Linux Kernel. In this flaw, an attacker with a local user privilege may cause a denial of service problem due to a BUG statement referencing pmd_t x. |
| A flaw was found in the Linux kernel’s IP framework for transforming packets (XFRM subsystem). This issue may allow a malicious user with CAP_NET_ADMIN privileges to directly dereference a NULL pointer in xfrm_update_ae_params(), leading to a possible kernel crash and denial of service. |
| A security vulnerability has been discovered within rpm-ostree, pertaining to the /etc/shadow file in default builds having the world-readable bit enabled. This issue arises from the default permissions being set at a higher level than recommended, potentially exposing sensitive authentication data to unauthorized access. |
| An out-of-bounds memory access flaw was found in the Linux kernel’s TUN/TAP device driver functionality in how a user generates a malicious (too big) networking packet when napi frags is enabled. This flaw allows a local user to crash or potentially escalate their privileges on the system. |
| A vulnerability was discovered in Samba, where the flaw allows SMB clients to truncate files, even with read-only permissions when the Samba VFS module "acl_xattr" is configured with "acl_xattr:ignore system acls = yes". The SMB protocol allows opening files when the client requests read-only access but then implicitly truncates the opened file to 0 bytes if the client specifies a separate OVERWRITE create disposition request. The issue arises in configurations that bypass kernel file system permissions checks, relying solely on Samba's permissions. |
| A vulnerability was found in PostgreSQL with the use of the MERGE command, which fails to test new rows against row security policies defined for UPDATE and SELECT. If UPDATE and SELECT policies forbid some rows that INSERT policies do not forbid, a user could store such rows. |
| A flaw was found in dogtag-pki and pki-core. The token authentication scheme can be bypassed with a LDAP injection. By passing the query string parameter sessionID=*, an attacker can authenticate with an existing session saved in the LDAP directory server, which may lead to escalation of privilege. |
| A use-after-free flaw was found in the Linux kernel's netfilter in the way a user triggers the nft_pipapo_remove function with the element, without a NFT_SET_EXT_KEY_END. This issue could allow a local user to crash the system or potentially escalate their privileges on the system. |
| A vulnerability was found in Samba's "rpcecho" development server, a non-Windows RPC server used to test Samba's DCE/RPC stack elements. This vulnerability stems from an RPC function that can be blocked indefinitely. The issue arises because the "rpcecho" service operates with only one worker in the main RPC task, allowing calls to the "rpcecho" server to be blocked for a specified time, causing service disruptions. This disruption is triggered by a "sleep()" call in the "dcesrv_echo_TestSleep()" function under specific conditions. Authenticated users or attackers can exploit this vulnerability to make calls to the "rpcecho" server, requesting it to block for a specified duration, effectively disrupting most services and leading to a complete denial of service on the AD DC. The DoS affects all other services as "rpcecho" runs in the main RPC task. |
