CVE-2021-47262 : Détail

CVE-2021-47262

7.1
/
Haute
0.04%V4
Local
2024-05-21
14h19 +00:00
2025-05-04
07h07 +00:00
CVE.org
NVD
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Descriptions du CVE

KVM: x86: Ensure liveliness of nested VM-Enter fail tracepoint message

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Ensure liveliness of nested VM-Enter fail tracepoint message Use the __string() machinery provided by the tracing subystem to make a copy of the string literals consumed by the "nested VM-Enter failed" tracepoint. A complete copy is necessary to ensure that the tracepoint can't outlive the data/memory it consumes and deference stale memory. Because the tracepoint itself is defined by kvm, if kvm-intel and/or kvm-amd are built as modules, the memory holding the string literals defined by the vendor modules will be freed when the module is unloaded, whereas the tracepoint and its data in the ring buffer will live until kvm is unloaded (or "indefinitely" if kvm is built-in). This bug has existed since the tracepoint was added, but was recently exposed by a new check in tracing to detect exactly this type of bug. fmt: '%s%s ' current_buffer: ' vmx_dirty_log_t-140127 [003] .... kvm_nested_vmenter_failed: ' WARNING: CPU: 3 PID: 140134 at kernel/trace/trace.c:3759 trace_check_vprintf+0x3be/0x3e0 CPU: 3 PID: 140134 Comm: less Not tainted 5.13.0-rc1-ce2e73ce600a-req #184 Hardware name: ASUS Q87M-E/Q87M-E, BIOS 1102 03/03/2014 RIP: 0010:trace_check_vprintf+0x3be/0x3e0 Code: <0f> 0b 44 8b 4c 24 1c e9 a9 fe ff ff c6 44 02 ff 00 49 8b 97 b0 20 RSP: 0018:ffffa895cc37bcb0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffffa895cc37bd08 RCX: 0000000000000027 RDX: 0000000000000027 RSI: 00000000ffffdfff RDI: ffff9766cfad74f8 RBP: ffffffffc0a041d4 R08: ffff9766cfad74f0 R09: ffffa895cc37bad8 R10: 0000000000000001 R11: 0000000000000001 R12: ffffffffc0a041d4 R13: ffffffffc0f4dba8 R14: 0000000000000000 R15: ffff976409f2c000 FS: 00007f92fa200740(0000) GS:ffff9766cfac0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000559bd11b0000 CR3: 000000019fbaa002 CR4: 00000000001726e0 Call Trace: trace_event_printf+0x5e/0x80 trace_raw_output_kvm_nested_vmenter_failed+0x3a/0x60 [kvm] print_trace_line+0x1dd/0x4e0 s_show+0x45/0x150 seq_read_iter+0x2d5/0x4c0 seq_read+0x106/0x150 vfs_read+0x98/0x180 ksys_read+0x5f/0xe0 do_syscall_64+0x40/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xae

Informations du CVE

Faiblesses connexes

CWE-ID Nom de la faiblesse Source
CWE Other No informations.

Métriques

Métriques Score Gravité CVSS Vecteur Source
V3.1 7.1 HIGH CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

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.

High

There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

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.

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EPSS

EPSS est un modèle de notation qui prédit la probabilité qu'une vulnérabilité soit exploitée.

Score EPSS

Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.

Percentile EPSS

Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.
EPSS First.org

Products Mentioned

Configuraton 0

Linux>>Linux_kernel >> Version From (including) 5.4 To (excluding) 5.4.126

Linux>>Linux_kernel >> Version From (including) 5.5 To (excluding) 5.10.44

Linux>>Linux_kernel >> Version From (including) 5.11 To (excluding) 5.12.11

Linux>>Linux_kernel >> Version 5.13

Linux>>Linux_kernel >> Version 5.13

Linux>>Linux_kernel >> Version 5.13

Linux>>Linux_kernel >> Version 5.13

Linux>>Linux_kernel >> Version 5.13

Références

Les informations affichées sur CVE Find proviennent de plusieurs sources de référence rigoureusement sélectionnées. Les données CVE sont fournies par MITRE Corporation et la National Vulnerability Database (NVD). Le catalogue des vulnérabilités activement exploitées (KEV) provient de la Cybersecurity and Infrastructure Security Agency (CISA), tandis que les scores EPSS sont issus de FIRST.org. Enfin, les données relatives aux faiblesses logicielles (CWE) et aux schémas d'attaque courants (CAPEC) sont maintenues par MITRE Corporation, et les informations sur les configurations logicielles et matérielles (CPE) proviennent du NVD.