CPE, qui signifie Common Platform Enumeration, est un système normalisé de dénomination du matériel, des logiciels et des systèmes d'exploitation. CPE fournit un schéma de dénomination structuré pour identifier et classer de manière unique les systèmes informatiques, les plates-formes et les progiciels sur la base de certains attributs tels que le fournisseur, le nom du produit, la version, la mise à jour, l'édition et la langue.
CWE, ou Common Weakness Enumeration, est une liste complète et une catégorisation des faiblesses et des vulnérabilités des logiciels. Elle sert de langage commun pour décrire les faiblesses de sécurité des logiciels au niveau de l'architecture, de la conception, du code ou de la mise en œuvre, qui peuvent entraîner des vulnérabilités.
CAPEC, qui signifie Common Attack Pattern Enumeration and Classification (énumération et classification des schémas d'attaque communs), est une ressource complète, accessible au public, qui documente les schémas d'attaque communs utilisés par les adversaires dans les cyberattaques. Cette base de connaissances vise à comprendre et à articuler les vulnérabilités communes et les méthodes utilisées par les attaquants pour les exploiter.
Services & Prix
Aides & Infos
Recherche de CVE id, CWE id, CAPEC id, vendeur ou mots clés dans les CVE
In the ServiceManager::add function in the hardware service manager, there is an insecure permissions check based on the PID of the caller which could allow an application or service to replace a HAL service with its own service. This could lead to a local elevation of privilege enabling code execution as a privileged process with no additional execution privileges needed. User interaction is not needed for exploitation. Product: Android. Versions: 8.0, 8.1. Android ID: A-68217907.
Missing Authorization The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Métriques
Métriques
Score
Gravité
CVSS Vecteur
Source
V3.0
7.8
HIGH
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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
A vulnerability exploitable with Local access means that the vulnerable component is not bound to the network stack, and the attacker's path is via read/write/execute capabilities. In some cases, the attacker may be logged in locally in order to exploit the vulnerability, otherwise, she may rely on User Interaction to execute a malicious file.
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 against the vulnerable component.
Privileges Required
This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.
Low
The attacker is authorized with (i.e. 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 may have the ability to cause an impact only to non-sensitive resources.
User Interaction
This metric captures the requirement for a 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
An important property captured by CVSS v3.0 is the ability for a vulnerability in one software component to impact resources beyond its means, or privileges.
Scope
Formally, Scope refers to the collection of privileges defined by a computing authority (e.g. an application, an operating system, or a sandbox environment) when granting access to computing resources (e.g. files, CPU, memory, etc). These privileges are assigned based on some method of identification and authorization. In some cases, the authorization may be simple or loosely controlled based upon predefined rules or standards. For example, in the case of Ethernet traffic sent to a network switch, the switch accepts traffic that arrives on its ports and is an authority that controls the traffic flow to other switch ports.
Unchanged
An exploited vulnerability can only affect resources managed by the same authority. In this case the vulnerable component and the impacted component are the same.
Base: Impact Metrics
The Impact metrics refer to the properties of the impacted component.
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 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.
High
There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 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 that one has in the description of a vulnerability.
Environmental Metrics
nvd@nist.gov
V2
7.2
AV:L/AC:L/Au:N/C:C/I:C/A:C
nvd@nist.gov
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.
Date
EPSS V0
EPSS V1
EPSS V2 (> 2022-02-04)
EPSS V3 (> 2025-03-07)
EPSS V4 (> 2025-03-17)
2021-04-18
3.3%
–
–
–
–
2021-09-05
–
3.3%
–
–
–
2022-01-09
–
3.3%
–
–
–
2022-01-30
–
3.3%
–
–
–
2022-02-06
–
–
2.9%
–
–
2022-03-06
–
–
2.9%
–
–
2022-03-27
–
–
2.52%
–
–
2022-04-03
–
–
2.52%
–
–
2022-06-19
–
–
2.52%
–
–
2022-12-25
–
–
2.52%
–
–
2023-01-01
–
–
2.52%
–
–
2023-02-26
–
–
2.52%
–
–
2023-03-12
–
–
–
0.31%
–
2023-06-11
–
–
–
0.31%
–
2023-10-01
–
–
–
0.43%
–
2023-10-29
–
–
–
0.62%
–
2023-11-26
–
–
–
0.43%
–
2023-12-24
–
–
–
0.31%
–
2024-02-11
–
–
–
0.31%
–
2024-06-02
–
–
–
0.31%
–
2024-11-24
–
–
–
0.31%
–
2024-12-22
–
–
–
1.37%
–
2025-01-19
–
–
–
1.37%
–
2025-03-18
–
–
–
–
0.47%
2025-03-18
–
–
–
–
0.47,%
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.
Date de publication : 2018-01-10 23h00 +00:00 Auteur : Google Security Research EDB Vérifié : Yes
This bug is similar to Jann Horn's issue (https://bugs.chromium.org/p/project-zero/issues/detail?id=851) -- credit should go to him.
The hardware service manager allows the registration of HAL services. These services are used by the vendor domain and other core processes, including system_server, surfaceflinger and hwservicemanager.
Similarly to the "regular" service manager ("servicemanager"), the hardware service manager is the context manager node for the "hwbinder" device, allowing it to mediate access to all hardware services registered under it. This is done by allowing its users to list, access or insert services into its registry, identified by a unique full-qualified name and an instance name (see http://androidxref.com/8.0.0_r4/xref/system/libhidl/transport/manager/1.0/IServiceManager.hal).
The "add" binder call allows callers to supply a binder instance to be registered with the hardware service manager. When issued, the call is unpacked by the auto-generated hidl stub, and then passed to "ServiceManager::add" for processing. Here is a snippet from that function (http://androidxref.com/8.0.0_r4/xref/system/hwservicemanager/ServiceManager.cpp#172):
1. Return<bool> ServiceManager::add(const hidl_string& name, const sp<IBase>& service) {
2. ...
3. // TODO(b/34235311): use HIDL way to determine this
4. // also, this assumes that the PID that is registering is the pid that is the service
5. pid_t pid = IPCThreadState::self()->getCallingPid();
6.
7. auto ret = service->interfaceChain([&](const auto &interfaceChain) {
8. if (interfaceChain.size() == 0) {
9. return;
10. }
11.
12. // First, verify you're allowed to add() the whole interface hierarchy
13. for(size_t i = 0; i < interfaceChain.size(); i++) {
14. std::string fqName = interfaceChain[i];
15. if (!mAcl.canAdd(fqName, pid)) {
16. return;
17. }
18. }
19. ...
20.}
As we can see in the snippet above, the function first records the pid of the calling process (populated into the transaction by the binder driver). Then, it issues a (non-oneway) transaction to the given service binder, in order to retrieve the list of interfaces corresponding to the given instance. As the comment correctly notes (lines 3-4), this approach is incorrect, for two reasons:
1. The given service can be hosted in a different process to the one making the binder call
2. Recording the pid does not guarantee that the calling process cannot transition from zombie to dead, allowing other processes to take its place
The pid is later used by the AccessControl class in order to perform the access control check, using getpidcon (http://androidxref.com/8.0.0_r4/xref/system/hwservicemanager/AccessControl.cpp#63). Consequently, an attack similar to the one proposed by Jann in the original bug is possible - namely, creating a race condition where the issuing process transitions to dead state, and a new privileged tid to be created in its place, causing the access control checks to be bypassed (by using the privileged process's SELinux context).
Furthermore, this code would have been susceptible to another vulnerability, by James Forshaw (https://bugs.chromium.org/p/project-zero/issues/detail?id=727) - namely, the caller can issue a "oneway" binder transaction in the "add" call, causing the calling pid field recorded by the driver to be zero. In such a case, getpidcon(0) is called, which would have returned the current process's context (the hardware service manager can register several critical services, including the "HIDL manager" and the "Token Manager"). However, this behaviour has since been changed in upstream libselinux (https://patchwork.kernel.org/patch/8395851/), making getpidcon(0) calls invalid, and therefore avoiding this issue.
However, an alternate exploit flow exists, which allows the issue to be exploited deterministically with no race condition required. Since the code above issues a non-oneway binder transaction on the given binder object, this allows the following attack flow to occur:
1. Process A creates a hardware binder service
2. Process A forks to create process B
3. Process B receives binder object from process A
4. Process B registers the binder object with the hardware service manager, by calling the "add" binder call
5. Hardware service manager executes "ServiceManager::add", records process B's pid, calls the (non-oneway) "interfaceChain" binder call on the given binder
6. Process A receives the "interfaceChain" binder call
7. Process A kills process B
8. Process A forks and kills the child processes, until reaching the pid before process B's pid
9. Process A calls the "loadSoundEffects" binder call on the "audio" service, spawning a new long-lived thread in system_server ("SoundPoolThread")
10. The new thread occupies process B's pid
11. Process A completes the "interfaceChain" transaction
12. Hardware service manager uses system_server's context to perform the ACL check
This attack flow allows a caller to replace any service published by system_server, including "IBase", "ISchedulingPolicyService" and "ISensorManager", or register any other services of behalf of system_server.
Note that in order to pass the binder instance between process A and process B, the "Token Manager" service can be used. This service allows callers to insert binder objects and retrieve 20-byte opaque tokens representing them. Subsequently, callers can supply the same 20-byte token, and retrieve the previously inserted binder object from the service. The service is accessible even to (non-isolated) app contexts (http://androidxref.com/8.0.0_r4/xref/system/sepolicy/private/app.te#188).
I'm attaching a PoC which performs the aforementioned attack flow, resulting in the "IBase" service (default instance) being hijacked. Running the PoC should result in the following output:
pid=23701
service manager: 0x7d0b44b000
token manager: 0x7d0b44b140
TOKEN: 0502010000000000B78268179E69C3B0EB6AEBFF60D82B42732F0FF853E8773379A005493648BCF1
05 02 01 00 00 00 00 00 B7 82 68 17 9E 69 C3 B0 EB 6A EB FF 60 D8 2B 42 73 2F 0F F8 53 E8 77 33 79 A0 05 49 36 48 BC F1
pid=23702
service manager: 0x72e544e000
token manager: 0x72e544e0a0
token manager returned binder: 0x72e544e140
Registering service...
interfaceChain called!
load: 0
Killing the child PID: 0
waitpid: 23702
Cycling to pid
unload: 0
load: 0
After running the PoC, the IBase service will be replaced with our own malicious service. This can be seen be running "lshal":
All binderized services (registered services through hwservicemanager)
Interface Server Clients
...
android.hidl.base@1.0::IBase/default 23701 (<-our pid) 463
Note that this attack can also be launched from an application context (with no required permissions), as apps can access both the "hwbinder" (http://androidxref.com/8.0.0_r4/xref/system/sepolicy/private/app.te#186) and the token service (http://androidxref.com/8.0.0_r4/xref/system/sepolicy/private/app.te#188).
The attached PoC should be built as part of the Android source tree, by extracting the source files into "frameworks/native/cmds/hwservice", and running a build (e.g., "mmm hwservice"). The resulting binary ("hwservice") contains the PoC code.
It should be noted that the hardware service manager uses the PID in all other calls ("get", "getTransport", "list", "listByInterface", "registerForNotifications", "debugDump", "registerPassthroughClient") as well.
These commands are all similarly racy (due to the getpidcon(...) usage), but are harder to exploit, as no binder call takes place prior to the ACL check.
Proof of Concept:
https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/43513.zip
