Redhat » Enterprise Linux Server : Security Vulnerabilities, CVEs, Published In 2017

The Linux kernel version 3.3-rc1 and later is affected by a vulnerability lies in the processing of incoming L2CAP commands - ConfigRequest, and ConfigResponse messages. This info leak is a result of uninitialized stack variables that may be returned to an attacker in their uninitialized state. By manipulating the code flows that precede the handling of these configuration messages, an attacker can also gain some control over which data will be held in the uninitialized stack variables. This can allow him to bypass KASLR, and stack canaries protection - as both pointers and stack canaries may be leaked in this manner. Combining this vulnerability (for example) with the previously disclosed RCE vulnerability in L2CAP configuration parsing (CVE-2017-1000251) may allow an attacker to exploit the RCE against kernels which were built with the above mitigations. These are the specifics of this vulnerability: In the function l2cap_parse_conf_rsp and in the function l2cap_parse_conf_req the following variable is declared without initialization: struct l2cap_conf_efs efs; In addition, when parsing input configuration parameters in both of these functions, the switch case for handling EFS elements may skip the memcpy call that will write to the efs variable: ... case L2CAP_CONF_EFS: if (olen == sizeof(efs)) memcpy(&efs, (void *)val, olen); ... The olen in the above if is attacker controlled, and regardless of that if, in both of these functions the efs variable would eventually be added to the outgoing configuration request that is being built: l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs), (unsigned long) &efs); So by sending a configuration request, or response, that contains an L2CAP_CONF_EFS element, but with an element length that is not sizeof(efs) - the memcpy to the uninitialized efs variable can be avoided, and the uninitialized variable would be returned to the attacker (16 bytes).

The Linux Kernel 2.6.32 and later are affected by a denial of service, by flooding the diagnostic port 0x80 an exception can be triggered leading to a kernel panic.

glibc contains a vulnerability that allows specially crafted LD_LIBRARY_PATH values to manipulate the heap/stack, causing them to alias, potentially resulting in arbitrary code execution. Please note that additional hardening changes have been made to glibc to prevent manipulation of stack and heap memory but these issues are not directly exploitable, as such they have not been given a CVE. This affects glibc 2.25 and earlier.

The native Bluetooth stack in the Linux Kernel (BlueZ), starting at the Linux kernel version 2.6.32 and up to and including 4.13.1, are vulnerable to a stack overflow vulnerability in the processing of L2CAP configuration responses resulting in Remote code execution in kernel space.

Mercurial prior to 4.3 did not adequately sanitize hostnames passed to ssh, leading to possible shell-injection attacks.

Mercurial prior to version 4.3 is vulnerable to a missing symlink check that can malicious repositories to modify files outside the repository

Linux kernel: heap out-of-bounds in AF_PACKET sockets. This new issue is analogous to previously disclosed CVE-2016-8655. In both cases, a socket option that changes socket state may race with safety checks in packet_set_ring. Previously with PACKET_VERSION. This time with PACKET_RESERVE. The solution is similar: lock the socket for the update. This issue may be exploitable, we did not investigate further. As this issue affects PF_PACKET sockets, it requires CAP_NET_RAW in the process namespace. But note that with user namespaces enabled, any process can create a namespace in which it has CAP_NET_RAW.

backend/comics/comics-document.c (aka the comic book backend) in GNOME Evince before 3.24.1 allows remote attackers to execute arbitrary commands via a .cbt file that is a TAR archive containing a filename beginning with a "--" command-line option substring, as demonstrated by a --checkpoint-action=exec=bash at the beginning of the filename.

JasPer 2.0.12 is vulnerable to a NULL pointer exception in the function jp2_encode which failed to check to see if the image contained at least one component resulting in a denial-of-service.

Ruby before 2.4.3 allows Net::FTP command injection. Net::FTP#get, getbinaryfile, gettextfile, put, putbinaryfile, and puttextfile use Kernel#open to open a local file. If the localfile argument starts with the "|" pipe character, the command following the pipe character is executed. The default value of localfile is File.basename(remotefile), so malicious FTP servers could cause arbitrary command execution.

elf/dl-load.c in the GNU C Library (aka glibc or libc6) 2.19 through 2.26 mishandles RPATH and RUNPATH containing $ORIGIN for a privileged (setuid or AT_SECURE) program, which allows local users to gain privileges via a Trojan horse library in the current working directory, related to the fillin_rpath and decompose_rpath functions. This is associated with misinterpretion of an empty RPATH/RUNPATH token as the "./" directory. NOTE: this configuration of RPATH/RUNPATH for a privileged program is apparently very uncommon; most likely, no such program is shipped with any common Linux distribution.

Tor Browser before 7.0.9 on macOS and Linux allows remote attackers to bypass the intended anonymity feature and discover a client IP address via vectors involving a crafted web site that leverages file:// mishandling in Firefox, aka TorMoil. NOTE: Tails is unaffected.

The process_open function in sftp-server.c in OpenSSH before 7.6 does not properly prevent write operations in readonly mode, which allows attackers to create zero-length files.

Samba before 4.7.3 might allow remote attackers to obtain sensitive information by leveraging failure of the server to clear allocated heap memory.

A non-privileged user is able to mount a fuse filesystem on RHEL 6 or 7 and crash a system if an application punches a hole in a file that does not end aligned to a page boundary.

Go before 1.8.4 and 1.9.x before 1.9.1 allows "go get" remote command execution. Using custom domains, it is possible to arrange things so that example.com/pkg1 points to a Subversion repository but example.com/pkg1/pkg2 points to a Git repository. If the Subversion repository includes a Git checkout in its pkg2 directory and some other work is done to ensure the proper ordering of operations, "go get" can be tricked into reusing this Git checkout for the fetch of code from pkg2. If the Subversion repository's Git checkout has malicious commands in .git/hooks/, they will execute on the system running "go get."

Use-after-free vulnerability in Samba 4.x before 4.7.3 allows remote attackers to execute arbitrary code via a crafted SMB1 request.

Integer underflow in the add_pseudoheader function in dnsmasq before 2.78 , when the --add-mac, --add-cpe-id or --add-subnet option is specified, allows remote attackers to cause a denial of service via a crafted DNS request.

Memory leak in dnsmasq before 2.78, when the --add-mac, --add-cpe-id or --add-subnet option is specified, allows remote attackers to cause a denial of service (memory consumption) via vectors involving DNS response creation.

dnsmasq before 2.78, when configured as a relay, allows remote attackers to obtain sensitive memory information via vectors involving handling DHCPv6 forwarded requests.

Stack-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted DHCPv6 request.

Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted IPv6 router advertisement request.

Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted DNS response.

Ruby through 2.2.7, 2.3.x through 2.3.4, and 2.4.x through 2.4.1 can expose arbitrary memory during a JSON.generate call. The issues lies in using strdup in ext/json/ext/generator/generator.c, which will stop after encountering a '\0' byte, returning a pointer to a string of length zero, which is not the length stored in space_len.

In dnsmasq before 2.78, if the DNS packet size does not match the expected size, the size parameter in a memset call gets a negative value. As it is an unsigned value, memset ends up writing up to 0xffffffff zero's (0xffffffffffffffff in 64 bit platforms), making dnsmasq crash.