Off-by-one Error

In mjs_json.c in Cesanta MongooseOS mJS 1.26, a maliciously formed JSON string can trigger an off-by-one heap-based buffer overflow in mjs_json_parse, which can potentially lead to redirection of control flow. NOTE: the original reporter disputes the significance of this finding because "there isn’t very much of an opportunity to exploit this reliably for an information leak, so there isn’t any real security impact."Show less

An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c has an off-by-one error (with a resultant integer underflow) affecting out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-10d2bb2e6b1d.Show less

Sudo before 1.9.5p2 contains an off-by-one error that can result in a heap-based buffer overflow, which allows privilege escalation to root via "sudoedit -s" and a command-line argument that ends with a single backslash character.Show less

An issue was discovered in Xen through 4.14.x allowing x86 HVM guest OS users to cause a denial of service (stack corruption), cause a data leak, or possibly gain privileges because of an off-by-one error. NOTE: this issue is caused by an incorrect fix for CVE-2020-27671.Show less

VMware ESXi (7.0 before ESXi_7.0.0-1.20.16321839, 6.7 before ESXi670-202004101-SG and 6.5 before ESXi650-202005401-SG), Workstation (15.x before 15.5.5), and Fusion (11.x before 11.5.5) contain an off-by-one heap-overflow vulnerability in the SVGA device. A malicious actor with local access to a virtual machine with 3D graphics enabled may be able to exploit this vulnerability to execute code on the hypervisor from a virtual machine. Additional conditions beyond the attacker's control must be present for exploitation to be possible.Show less

An off-by-one error in the Zephyr project MQTT packet length decoder can result in memory corruption and possible remote code execution. NCC-ZEP-031 This issue affects: zephyrproject-rtos zephyr version 2.2.0 and later versions.Show less

An off-by-one error in the DecodeBlock function in codec/sdl_image.c in VideoLAN VLC media player before 3.0.9 allows remote attackers to cause a denial of service (memory corruption) via a crafted image file. NOTE: this may be related to the SDL_Image product.Show less

An issue was discovered in Squid through 4.7. When Squid is parsing ESI, it keeps the ESI elements in ESIContext. ESIContext contains a buffer for holding a stack of ESIElements. When a new ESIElement is parsed, it is added via addStackElement. addStackElement has a check for the number of elements in this buffer, but it's off by 1, leading to a Heap Overflow of 1 element. The overflow is within the same structure so it can't affect adjacent memory blocks, and thus just leads to a crash while processing.Show less

An off by one issue existed in the handling of racoon configuration files. This issue was addressed through improved bounds checking. This issue is fixed in iOS 13.3.1 and iPadOS 13.3.1, macOS Catalina 10.15.3, tvOS 13.3.1. Loading a maliciously crafted racoon configuration file may lead to arbitrary code execution.Show less

In OSSEC-HIDS 2.7 through 3.5.0, the server component responsible for log analysis (ossec-analysisd) is vulnerable to an off-by-one heap-based buffer overflow during the cleaning of crafted syslog msgs (received from authenticated remote agents and delivered to the analysisd processing queue by ossec-remoted).Show less

cyrus-sasl (aka Cyrus SASL) 2.1.27 has an out-of-bounds write leading to unauthenticated remote denial-of-service in OpenLDAP via a malformed LDAP packet. The OpenLDAP crash is ultimately caused by an off-by-one error in _sasl_add_string in common.c in cyrus-sasl.Show less

An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service via a XENMEM_add_to_physmap hypercall. p2m->max_mapped_gfn is used by the functions p2m_resolve_translation_fault() and p2m_get_entry() to sanity check guest physical frame. The rest of the code in the two functions will assume that there is a valid root table and check that with BUG_ON(). The function p2m_get_root_pointer() will ignore the unused top bits of a guest physical frame. This means that the function p2m_set_entry() will alias the frame. However, p2m->max_mapped_gfn will be updated using the original frame. It would be possible to set p2m->max_mapped_gfn high enough to cover a frame that would lead p2m_get_root_pointer() to return NULL in p2m_get_entry() and p2m_resolve_translation_fault(). Additionally, the sanity check on p2m->max_mapped_gfn is off-by-one allowing "highest mapped + 1" to be considered valid. However, p2m_get_root_pointer() will return NULL. The problem could be triggered with a specially crafted hypercall XENMEM_add_to_physmap{, _batch} followed by an access to an address (via hypercall or direct access) that passes the sanity check but cause p2m_get_root_pointer() to return NULL. A malicious guest administrator may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen version 4.8 and newer are vulnerable. Only Arm systems are vulnerable. x86 systems are not affected.Show less