Null Pointer Dereference
A null pointer dereference occurs when a program attempts to access memory through a pointer that has been set to NULL (address 0x0).
How It Works
A null pointer dereference occurs when a program attempts to access memory through a pointer that has been set to NULL (address 0x0). In normal operation, pointers should reference valid memory locations before use. When a pointer is NULL—either uninitialized, explicitly set to NULL, or returned as NULL from a failed allocation—and the program tries to read from, write to, or execute code at that address, the operating system intervenes. On modern systems, accessing address zero triggers a segmentation fault that immediately terminates the process.
Attackers exploit this by manipulating program logic to force null pointer conditions. Common techniques include triggering allocation failures in low-memory conditions, providing malformed input that bypasses initialization checks, or exploiting race conditions where a pointer is checked for NULL but becomes NULL before use. The attacker identifies code paths where null checks are missing or inadequate, then crafts inputs to reach those vulnerable states.
On legacy systems without memory protection, attackers could map their own code at address zero, converting a crash into arbitrary code execution. Modern operating systems prevent this through mmap_min_addr restrictions that prohibit mapping memory below a threshold (typically 64KB). This mitigation has largely relegated null pointer dereferences to denial-of-service attacks rather than remote code execution vectors.
Impact
- Service disruption: Immediate process crash, taking down the vulnerable application or daemon
- Availability attacks: Repeated crashes forcing system restarts or service downtime
- Limited code execution: On unpatched legacy systems (pre-2009 Linux kernels, older embedded devices) where address zero mapping is possible
- Privilege escalation: In kernel-mode drivers where null dereferences can be exploited to execute attacker code with system privileges
Real-World Examples
The Linux kernel suffered from CVE-2009-2908, where null pointer dereferences in various subsystems could be exploited on systems allowing mmap at address zero. Attackers could map malicious code at NULL and trigger kernel null dereferences to achieve privilege escalation. This prompted the introduction of mmap_min_addr protections.
Microsoft Windows drivers have been frequent targets, including CVE-2020-17087 in the Windows kernel cryptography driver. Attackers triggered null pointer dereferences in kernel mode, which on older Windows versions could be exploited for local privilege escalation by controlling the null page.
Web browsers have experienced denial-of-service through null dereferences when parsing malformed content. Firefox CVE-2019-11707 involved a null pointer dereference in the IonMonkey JIT compiler, allowing attackers to crash the browser with specially crafted JavaScript, though not achieve code execution due to modern protections.
Mitigation
- Explicit null checks: Validate all pointers before dereferencing, especially after allocation or function calls that may return NULL
- Static analysis tools: Deploy analyzers like Coverity, Clang Static Analyzer, or PVS-Studio to detect missing null checks during development
- Address space layout: Enable
mmap_min_addrkernel protection (standard on modern Linux, typically 65536 bytes) - Fuzzing: Use AFL, libFuzzer, or similar tools to stress-test error handling paths and allocation failures
- Safe coding practices: Initialize pointers to NULL, use smart pointers in C++, adopt languages with built-in null safety
- Runtime bounds checking: Enable AddressSanitizer during testing to catch null dereferences immediately
Recent CVEs (4134)
VMware ESXi contains a null-pointer deference vulnerability. Rated medium severity (CVSS 6.5), this vulnerability is low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
In ISC DHCP 4.4.0 -> 4.4.3, ISC DHCP 4.1-ESV-R1 -> 4.1-ESV-R16-P1, when the function option_code_hash_lookup() is called from add_option(), it increases the option's refcount field. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in Veritas NetBackup through 8.2 and related Veritas products. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
An issue was discovered in Xpdf 4.04. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in Bento4 through 1.6.0-639. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
NULL Pointer Dereference in GitHub repository vim/vim prior to 8.2.4959. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
NULL Pointer Dereference in GitHub repository vim/vim prior to 9.0.0552. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
A null pointer dereference was addressed with improved validation. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
MZ Automation's libIEC61850 (versions 1.4 and prior; version 1.5 prior to commit a3b04b7bc4872a5a39e5de3fdc5fbde52c09e10e) uses a NULL pointer in certain situations. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
XPDF 4.04 is vulnerable to Null Pointer Dereference in FoFiType1C.cc:2393. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in Bento4 through 1.6.0-639. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in Bento4 through 1.6.0-639. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
TensorFlow is an open source platform for machine learning. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
TensorFlow is an open source platform for machine learning. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
TensorFlow is an open source platform for machine learning. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
TensorFlow is an open source platform for machine learning. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
A NULL pointer dereference issue in the TEE_MACCompareFinal function in Samsung mTower through 0.3.0 allows a trusted application to trigger a Denial of Service (DoS) by invoking the function. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
TensorFlow is an open source platform for machine learning. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
An issue was discovered in Bento4 through 1.6.0-639. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A null pointer dereference issue was discovered in fs/io_uring.c in the Linux kernel before 5.15.62. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity.
A NULL pointer dereference flaw in diFree in fs/jfs/inode.c in Journaled File System (JFS)in the Linux kernel. Rated high severity (CVSS 7.1), this vulnerability is low attack complexity.
LIEF commit 365a16a was discovered to contain a segmentation violation via the component CoreFile.tcc:69. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
LIEF commit 5d1d643 was discovered to contain a segmentation violation via the function LIEF::MachO::SegmentCommand::file_offset() at /MachO/SegmentCommand.cpp. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
In lighttpd 1.4.65, mod_wstunnel does not initialize a handler function pointer if an invalid HTTP request (websocket handshake) is received. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A NULL pointer dereference vulnerability was found in vmwgfx driver in drivers/gpu/vmxgfx/vmxgfx_execbuf.c in GPU component of Linux kernel with device file '/dev/dri/renderD128 (or Dxxx)'. Rated medium severity (CVSS 6.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
NULL Pointer Dereference in GitHub repository vim/vim prior to 9.0.0404. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
xhyve commit dfbe09b was discovered to contain a NULL pointer dereference via the component vi_pci_read(). Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
xhyve commit dfbe09b was discovered to contain a NULL pointer dereference via the component vi_pci_write(). Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
There is a NULL pointer dereference in aes256_encrypt in Samsung mTower through 0.3.0 due to a missing check on the return value of EVP_CIPHER_CTX_new. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in the Linux kernel through 5.16-rc6. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
Samsung Electronics mTower v0.3.0 and earlier was discovered to contain a NULL pointer dereference via the function TEE_GetObjectInfo1. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Samsung Electronics mTower v0.3.0 and earlier was discovered to contain a NULL pointer dereference via the function TEE_AllocateTransientObject. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A flaw was found in the Linux kernel’s KVM when attempting to set a SynIC IRQ. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. Public exploit code available.
A NULL pointer dereference issue was found in KVM when releasing a vCPU with dirty ring support enabled. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. Public exploit code available.
telnetd in GNU Inetutils through 2.3, MIT krb5-appl through 1.0.3, and derivative works has a NULL pointer dereference via 0xff 0xf7 or 0xff 0xf8. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
A denial of service (DOS) issue was found in the Linux kernel’s smb2_ioctl_query_info function in the fs/cifs/smb2ops.c Common Internet File System (CIFS) due to an incorrect return from the. Rated medium severity (CVSS 4.4), this vulnerability is low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
NULL Pointer Dereference in GitHub repository vim/vim prior to 9.0.0259. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
NULL Pointer Dereference in GitHub repository vim/vim prior to 9.0.0240. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
NULL Pointer Dereference in GitHub repository vim/vim prior to 9.0.0224. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
A crafted HTTP packet without a content-type header can create a denial-of-service condition in Softing Secure Integration Server V1.22. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A crafted HTTP packet with a missing HTTP URI can create a denial-of-service condition in Softing Secure Integration Server V1.22. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Softing OPC UA C++ Server SDK, Secure Integration Server, edgeConnector, edgeAggregator, OPC Suite, and uaGate are affected by a NULL pointer dereference vulnerability. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A Null Pointer dereference vulnerability exists in GPAC 2.1-DEV-revUNKNOWN-master via the function gf_filter_pid_set_property_full () at filter_core/filter_pid.c:5250,which causes a Denial of Service. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
tifig v0.2.2 was discovered to contain a segmentation violation via std::vector<unsigned int, std::allocator<unsigned int> >::size() const at /bits/stl_vector.h. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
tifig v0.2.2 was discovered to contain a segmentation violation via getType() at /common/bbox.cpp. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
OTFCC v0.10.4 was discovered to contain a segmentation violation via /release-x64/otfccdump+0x6b6a8f. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
SWFTools commit 772e55a2 was discovered to contain a segmentation violation via DCTStream::getChar() at /xpdf/Stream.cc. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
In Bluetooth, there are possible process crashes due to dereferencing a null pointer. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is a possible crash due to a missing null check. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Foxit PDF Reader before 12.0.1 and PDF Editor before 12.0.1 allow a NULL pointer dereference when this.Span is used for oState of Collab.addStateModel, because this.Span.text can be NULL. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Foxit PDF Reader before 12.0.1 and PDF Editor before 12.0.1 allow an exportXFAData NULL pointer dereference. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
NVIDIA vGPU software contains a vulnerability in the Virtual GPU Manager (vGPU plugin), where it can dereference a null pointer, which may lead to denial of service. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
In BIG-IP Versions 16.1.x before 16.1.3.1, 15.1.x before 15.1.6.1, and 14.1.x before 14.1.5.1, when a BIG-IP APM access policy is configured on a virtual server, undisclosed traffic can cause the. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In BIG-IP Versions 16.1.x before 16.1.3.1 and 15.1.x before 15.1.6.1, when an LTM Client or Server SSL profile with TLS 1.3 enabled is configured on a virtual server, along with an iRule that calls. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
PingCAP TiDB v6.1.0 was discovered to contain a NULL pointer dereference. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
The package io.socket:socket.io-client before 2.0.1 are vulnerable to NULL Pointer Dereference when parsing a packet with with invalid payload format. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
PicoC v3.2.2 was discovered to contain a NULL pointer dereference at variable.c. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
NULL Pointer Dereference in GitHub repository gpac/gpac prior to v2.1.0-DEV. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
A NULL pointer dereference flaw was found in rxrpc_preparse_s in net/rxrpc/server_key.c in the Linux kernel. Rated high severity (CVSS 7.1), this vulnerability is low attack complexity.
Insufficient validation of trust input in WebOTP in Google Chrome on Android prior to 100.0.4896.60 allowed a remote attacker to send arbitrary intents from any app via a malicious app. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Radare2 v5.7.2 was discovered to contain a NULL pointer dereference via the function r_bin_file_xtr_load_buffer at bin/bfile.c. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A NULL Pointer Dereference vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on QFX5000 Series and MX Series allows an unauthenticated adjacent attacker to cause a. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in dbus-broker before 31. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Toybox v0.8.7 was discovered to contain a NULL pointer dereference via the component httpd.c. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A CWE-476: NULL Pointer Dereference vulnerability exists that could cause a denial of service of the webserver when parsing JSON content type. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
The frame scheduling module has a null pointer dereference vulnerability. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
The frame scheduling module has a null pointer dereference vulnerability. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
NULL Pointer Dereference allows attackers to cause a denial of service (or application crash). Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
NULL Pointer Dereference in GitHub repository bfabiszewski/libmobi prior to 0.11. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
A NULL pointer dereference flaw was found in the Linux kernel’s KVM module, which can lead to a denial of service in the x86_emulate_insn in arch/x86/kvm/emulate.c. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity.
NULL Pointer Dereference in GitHub repository vim/vim prior to 8.2. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
KubeEdge is built upon Kubernetes and extends native containerized application orchestration and device management to hosts at the Edge. Rated medium severity (CVSS 5.7), this vulnerability is remotely exploitable, low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
KubeEdge is built upon Kubernetes and extends native containerized application orchestration and device management to hosts at the Edge. Rated medium severity (CVSS 5.7), this vulnerability is low attack complexity. Public exploit code available.
NULL Pointer Dereference in GitHub repository vim/vim prior to 8.2.5163. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
OFFIS DCMTK's (All versions prior to 3.6.7) has a NULL pointer dereference vulnerability while processing DICOM files, which may result in a denial-of-service condition. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A NULL pointer dereference vulnerability was found in Ghostscript, which occurs when it tries to render a large number of bits in memory. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
Microsoft Windows SMBv3 suffers from a null pointer dereference in versions of Windows prior to the April, 2022 patch set. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
The kernel module has the null pointer and out-of-bounds array vulnerabilities. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
Envoy is a cloud-native high-performance proxy. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
In libjpeg 1.63, there is a NULL pointer dereference in LineBuffer::FetchRegion in linebuffer.cpp. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
In libjpeg 1.63, there is a NULL pointer dereference in Component::SubXOf in component.hpp. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
libmobi before v0.10 contains a NULL pointer dereference via the component mobi_buffer_getpointer. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Unicorn Engine v2.0.0-rc7 and below was discovered to contain a NULL pointer dereference via qemu_ram_free. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
With shadow paging enabled, the INVPCID instruction results in a call to kvm_mmu_invpcid_gva. Rated medium severity (CVSS 6.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
TensorFlow is an open source platform for machine learning. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. Public exploit code available.
A vulnerability has been identified in JT2Go (All versions < V13.3.0.3), Teamcenter Visualization V13.3 (All versions < V13.3.0.3), Teamcenter Visualization V14.0 (All versions < V14.0.0.1). Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
A vulnerability has been identified in JT2Go (All versions < V13.3.0.3), Teamcenter Visualization V13.3 (All versions < V13.3.0.3), Teamcenter Visualization V14.0 (All versions < V14.0.0.1). Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
In Artifex MuJS through 1.2.0, jsP_dumpsyntax in jsdump.c has a NULL pointer dereference, as demonstrated by mujs-pp. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
NVIDIA GPU Display Driver for Windows contains a vulnerability in the kernel mode layer (nvlddmkm.sys) handler for DxgkDdiEscape, where a NULL pointer dereference may lead to a system crash. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity.
The frame scheduling module has a null pointer dereference vulnerability. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.