CVE Descriptions

In the Linux kernel, the following vulnerability has been resolved: APEI/GHES: ensure that won't go past CPER allocated record The logic at ghes_new() prevents allocating too large records, by checking if they're bigger than GHES_ESTATUS_MAX_SIZE (currently, 64KB). Yet, the allocation is done with the actual number of pages from the CPER bios table location, which can be smaller. Yet, a bad firmware could send data with a different size, which might be bigger than the allocated memory, causing an OOPS: Unable to handle kernel paging request at virtual address fff00000f9b40000 Mem abort info: ESR = 0x0000000096000007 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x07: level 3 translation fault Data abort info: ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 swapper pgtable: 4k pages, 52-bit VAs, pgdp=000000008ba16000 [fff00000f9b40000] pgd=180000013ffff403, p4d=180000013fffe403, pud=180000013f85b403, pmd=180000013f68d403, pte=0000000000000000 Internal error: Oops: 0000000096000007 [#1] SMP Modules linked in: CPU: 0 UID: 0 PID: 303 Comm: kworker/0:1 Not tainted 6.19.0-rc1-00002-gda407d200220 #34 PREEMPT Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 02/02/2022 Workqueue: kacpi_notify acpi_os_execute_deferred pstate: 214020c5 (nzCv daIF +PAN -UAO -TCO +DIT -SSBS BTYPE=--) pc : hex_dump_to_buffer+0x30c/0x4a0 lr : hex_dump_to_buffer+0x328/0x4a0 sp : ffff800080e13880 x29: ffff800080e13880 x28: ffffac9aba86f6a8 x27: 0000000000000083 x26: fff00000f9b3fffc x25: 0000000000000004 x24: 0000000000000004 x23: ffff800080e13905 x22: 0000000000000010 x21: 0000000000000083 x20: 0000000000000001 x19: 0000000000000008 x18: 0000000000000010 x17: 0000000000000001 x16: 00000007c7f20fec x15: 0000000000000020 x14: 0000000000000008 x13: 0000000000081020 x12: 0000000000000008 x11: ffff800080e13905 x10: ffff800080e13988 x9 : 0000000000000000 x8 : 0000000000000000 x7 : 0000000000000001 x6 : 0000000000000020 x5 : 0000000000000030 x4 : 00000000fffffffe x3 : 0000000000000000 x2 : ffffac9aba78c1c8 x1 : ffffac9aba76d0a8 x0 : 0000000000000008 Call trace: hex_dump_to_buffer+0x30c/0x4a0 (P) print_hex_dump+0xac/0x170 cper_estatus_print_section+0x90c/0x968 cper_estatus_print+0xf0/0x158 __ghes_print_estatus+0xa0/0x148 ghes_proc+0x1bc/0x220 ghes_notify_hed+0x5c/0xb8 notifier_call_chain+0x78/0x148 blocking_notifier_call_chain+0x4c/0x80 acpi_hed_notify+0x28/0x40 acpi_ev_notify_dispatch+0x50/0x80 acpi_os_execute_deferred+0x24/0x48 process_one_work+0x15c/0x3b0 worker_thread+0x2d0/0x400 kthread+0x148/0x228 ret_from_fork+0x10/0x20 Code: 6b14033f 540001ad a94707e2 f100029f (b8747b44) ---[ end trace 0000000000000000 ]--- Prevent that by taking the actual allocated are into account when checking for CPER length. [ rjw: Subject tweaks ]

CVE Informations

Related Weaknesses

CWE-ID	Weakness Name	Source
CWE Other	No informations.

Metrics

Metrics	Score	Severity	CVSS Vector	Source
V3.1	5.5	MEDIUM	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H More informations Base: Exploitabilty Metrics The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack Vector This metric reflects the context by which vulnerability exploitation is possible. Local The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Attack Complexity This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Low Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. Low The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources. User Interaction This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component. None The vulnerable system can be exploited without interaction from any user. Base: Scope Metrics The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope. Scope Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs. Unchanged An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority. Base: Impact Metrics The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve. Confidentiality Impact This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. None There is no loss of confidentiality within the impacted component. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. None There is no loss of integrity within the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. High There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal Metrics The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability. Environmental Metrics These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.	nvd@nist.gov

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.

EPSS First.org