CWE-287
DiscouragedImproper Authentication
Abstraction: Class · Status: Draft
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
6877 vulnerabilities reference this CWE, most recent first.
GHSA-84HJ-V72F-GXC9
Vulnerability from github – Published: 2023-08-28 21:31 – Updated: 2024-03-12 18:31Zoho ManageEngine ADManager Plus through 7186 is vulnerable to 2FA bypass.
{
"affected": [],
"aliases": [
"CVE-2023-35785"
],
"database_specific": {
"cwe_ids": [
"CWE-287"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-08-28T20:15:08Z",
"severity": "HIGH"
},
"details": "Zoho ManageEngine ADManager Plus through 7186 is vulnerable to 2FA bypass.",
"id": "GHSA-84hj-v72f-gxc9",
"modified": "2024-03-12T18:31:11Z",
"published": "2023-08-28T21:31:06Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-35785"
},
{
"type": "WEB",
"url": "https://manageengine.com"
},
{
"type": "WEB",
"url": "https://www.manageengine.com/security/advisory/CVE/CVE-2023-35785.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-84M5-WQ3J-47C4
Vulnerability from github – Published: 2023-12-25 09:30 – Updated: 2024-01-04 03:30An issue was discovered in RWS WorldServer before 11.7.3. Adding a token parameter with the value of 02 bypasses all authentication requirements. Arbitrary Java code can be uploaded and executed via a .jar archive to the ws-api/v2/customizations/api endpoint.
{
"affected": [],
"aliases": [
"CVE-2022-34267"
],
"database_specific": {
"cwe_ids": [
"CWE-287"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-12-25T08:15:07Z",
"severity": "CRITICAL"
},
"details": "An issue was discovered in RWS WorldServer before 11.7.3. Adding a token parameter with the value of 02 bypasses all authentication requirements. Arbitrary Java code can be uploaded and executed via a .jar archive to the ws-api/v2/customizations/api endpoint.",
"id": "GHSA-84m5-wq3j-47c4",
"modified": "2024-01-04T03:30:38Z",
"published": "2023-12-25T09:30:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-34267"
},
{
"type": "WEB",
"url": "https://www.rws.com/localization/products/trados-enterprise/worldserver"
},
{
"type": "WEB",
"url": "https://www.triskelelabs.com/vulnerabilities-in-rws-worldserver"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-84MC-CXQ8-4H6R
Vulnerability from github – Published: 2026-10-09 15:31 – Updated: 2026-10-09 15:31PHPNuxBill through 2025.3.20 contains an authentication bypass vulnerability in RADIUS CHAP verification because Password::chap_verify() returns true when the supplied response does not match. Attackers who know a valid customer or PPPoE username can log in through MikroTik hotspot or PPPoE CHAP with any incorrect password to obtain network access and consume that customer's plan.
{
"affected": [],
"aliases": [
"CVE-2026-108108"
],
"database_specific": {
"cwe_ids": [
"CWE-287"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-10-09T15:17:11Z",
"severity": "HIGH"
},
"details": "PHPNuxBill through 2025.3.20 contains an authentication bypass vulnerability in RADIUS CHAP verification because Password::chap_verify() returns true when the supplied response does not match. Attackers who know a valid customer or PPPoE username can log in through MikroTik hotspot or PPPoE CHAP with any incorrect password to obtain network access and consume that customer\u0027s plan.",
"id": "GHSA-84mc-cxq8-4h6r",
"modified": "2026-10-09T15:31:33Z",
"published": "2026-10-09T15:31:33Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/hotspotbilling/phpnuxbill/security/advisories/GHSA-6f62-x25v-9686"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-108108"
},
{
"type": "WEB",
"url": "https://github.com/hotspotbilling/phpnuxbill"
},
{
"type": "WEB",
"url": "https://github.com/hotspotbilling/phpnuxbill/blob/2025.3.13/system/autoload/Password.php#L48"
},
{
"type": "WEB",
"url": "https://www.vulncheck.com/advisories/phpnuxbill-through-2025.3.20-chap-authentication-bypass-via-password-chap-verify"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-84QR-WGJ8-H8V8
Vulnerability from github – Published: 2022-05-17 04:41 – Updated: 2022-05-17 04:41Unspecified vulnerability in Citrix VDI-In-A-Box 5.3.x before 5.3.8 and 5.4.x before 5.4.4 allows remote attackers to bypass authentication via unspecified vectors, related to a Java servlet.
{
"affected": [],
"aliases": [
"CVE-2014-3780"
],
"database_specific": {
"cwe_ids": [
"CWE-287"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2014-05-30T14:55:00Z",
"severity": "HIGH"
},
"details": "Unspecified vulnerability in Citrix VDI-In-A-Box 5.3.x before 5.3.8 and 5.4.x before 5.4.4 allows remote attackers to bypass authentication via unspecified vectors, related to a Java servlet.",
"id": "GHSA-84qr-wgj8-h8v8",
"modified": "2022-05-17T04:41:28Z",
"published": "2022-05-17T04:41:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2014-3780"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/58431"
},
{
"type": "WEB",
"url": "http://support.citrix.com/article/CTX140779"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/67687"
},
{
"type": "WEB",
"url": "http://www.securitytracker.com/id/1030305"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-84R5-FG22-5VJV
Vulnerability from github – Published: 2026-07-14 18:32 – Updated: 2026-07-14 18:32Improper authentication in Azure Spring Apps allows an authorized attacker to elevate privileges over a network.
{
"affected": [],
"aliases": [
"CVE-2026-50338"
],
"database_specific": {
"cwe_ids": [
"CWE-287"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-14T17:17:00Z",
"severity": "HIGH"
},
"details": "Improper authentication in Azure Spring Apps allows an authorized attacker to elevate privileges over a network.",
"id": "GHSA-84r5-fg22-5vjv",
"modified": "2026-07-14T18:32:04Z",
"published": "2026-07-14T18:32:04Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50338"
},
{
"type": "WEB",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50338"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-84XH-PWC6-7G4G
Vulnerability from github – Published: 2025-02-05 18:34 – Updated: 2026-01-27 15:30When multiple server blocks are configured to share the same IP address and port, an attacker can use session resumption to bypass client certificate authentication requirements on these servers. This vulnerability arises when TLS Session Tickets https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_ticket_key are used and/or the SSL session cache https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_cache are used in the default server and the default server is performing client certificate authentication.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
{
"affected": [],
"aliases": [
"CVE-2025-23419"
],
"database_specific": {
"cwe_ids": [
"CWE-287",
"CWE-613",
"CWE-863"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-02-05T18:15:33Z",
"severity": "MODERATE"
},
"details": "When multiple server blocks are configured to share the same IP address and port, an attacker can use session resumption to bypass client certificate authentication requirements on these servers. This vulnerability arises when TLS Session Tickets https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_ticket_key are used and/or the SSL session cache https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_cache are used in the default server and the default server is performing client certificate authentication.\u00a0\u00a0\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated.",
"id": "GHSA-84xh-pwc6-7g4g",
"modified": "2026-01-27T15:30:26Z",
"published": "2025-02-05T18:34:46Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-23419"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00017.html"
},
{
"type": "WEB",
"url": "https://my.f5.com/manage/s/article/K000149173"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2025/02/05/8"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-84XP-PHCJ-753R
Vulnerability from github – Published: 2022-05-24 22:28 – Updated: 2022-10-27 19:00The management page of the Orca HCM digital learning platform does not perform identity verification, which allows remote attackers to execute the management function without logging in, access members’ information, modify and delete the courses in system, thus causing users fail to access the learning content.
{
"affected": [],
"aliases": [
"CVE-2021-35964"
],
"database_specific": {
"cwe_ids": [
"CWE-285",
"CWE-287"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-07-19T12:15:00Z",
"severity": "HIGH"
},
"details": "The management page of the Orca HCM digital learning platform does not perform identity verification, which allows remote attackers to execute the management function without logging in, access members\u2019 information, modify and delete the courses in system, thus causing users fail to access the learning content.",
"id": "GHSA-84xp-phcj-753r",
"modified": "2022-10-27T19:00:41Z",
"published": "2022-05-24T22:28:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-35964"
},
{
"type": "WEB",
"url": "https://www.chtsecurity.com/news/ba7b3ae7-14f3-4970-b3f6-4d97d8c7ea25"
},
{
"type": "WEB",
"url": "https://www.twcert.org.tw/tw/cp-132-4924-f74d5-1.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-8545-G96P-Q9HH
Vulnerability from github – Published: 2022-05-17 03:37 – Updated: 2025-04-12 12:45The rsaauth extension in TYPO3 4.3.0 through 4.3.14, 4.4.0 through 4.4.15, 4.5.0 through 4.5.39, and 4.6.0 through 4.6.18, when configured for the frontend, allows remote attackers to bypass authentication via a password that is casted to an empty value.
{
"affected": [],
"aliases": [
"CVE-2015-2047"
],
"database_specific": {
"cwe_ids": [
"CWE-287"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2015-02-23T17:59:00Z",
"severity": "LOW"
},
"details": "The rsaauth extension in TYPO3 4.3.0 through 4.3.14, 4.4.0 through 4.4.15, 4.5.0 through 4.5.39, and 4.6.0 through 4.6.18, when configured for the frontend, allows remote attackers to bypass authentication via a password that is casted to an empty value.",
"id": "GHSA-8545-g96p-q9hh",
"modified": "2025-04-12T12:45:33Z",
"published": "2022-05-17T03:37:46Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2015-2047"
},
{
"type": "WEB",
"url": "https://review.typo3.org/#/c/37013"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-updates/2016-08/msg00106.html"
},
{
"type": "WEB",
"url": "http://typo3.org/teams/security/security-bulletins/typo3-core/typo3-core-sa-2015-001"
},
{
"type": "WEB",
"url": "http://www.debian.org/security/2015/dsa-3164"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2015/02/22/4"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2015/02/22/8"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/72763"
},
{
"type": "WEB",
"url": "http://www.securitytracker.com/id/1031824"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-856Q-XV3C-7F2F
Vulnerability from github – Published: 2022-02-23 14:59 – Updated: 2022-02-25 15:38Impact
The Istio control plane, istiod, is vulnerable to a request processing error, allowing a malicious attacker that sends a specially crafted message which results in the control plane crashing. This endpoint is served over TLS port 15012, but does not require any authentication from the attacker.
For simple installations, Istiod is typically only reachable from within the cluster, limiting the blast radius. However, for some deployments, especially multicluster topologies, this port is exposed over the public internet.
Patches
- Istio 1.13.1 and above
- Istio 1.12.4 and above
- Istio 1.11.7 and above
Workarounds
There are no effective workarounds, beyond upgrading. Limiting network access to Istiod to the minimal set of clients can help lessen the scope of the vulnerability to some extent.
References
More details can be found in the Istio Security Bulletin
For more information
If you have any questions or comments about this advisory, please email us at istio-security-vulnerability-reports@googlegroups.com
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "istio.io/istio"
},
"ranges": [
{
"events": [
{
"introduced": "1.13.0"
},
{
"fixed": "1.13.1"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.13.0"
]
},
{
"package": {
"ecosystem": "Go",
"name": "istio.io/istio"
},
"ranges": [
{
"events": [
{
"introduced": "1.12.0"
},
{
"fixed": "1.12.4"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Go",
"name": "istio.io/istio"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.11.7"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2022-23635"
],
"database_specific": {
"cwe_ids": [
"CWE-1284",
"CWE-287"
],
"github_reviewed": true,
"github_reviewed_at": "2022-02-23T14:59:08Z",
"nvd_published_at": "2022-02-22T22:15:00Z",
"severity": "HIGH"
},
"details": "### Impact\nThe Istio control plane, `istiod`, is vulnerable to a request processing error, allowing a malicious attacker that sends a specially crafted message which results in the control plane crashing. This endpoint is served over TLS port 15012, but does not require any authentication from the attacker.\n\nFor simple installations, Istiod is typically only reachable from within the cluster, limiting the blast radius. However, for some deployments, especially [multicluster](https://istio.io/latest/docs/setup/install/multicluster/primary-remote/) topologies, this port is exposed over the public internet.\n\n### Patches\n\n- Istio 1.13.1 and above\n- Istio 1.12.4 and above\n- Istio 1.11.7 and above\n\n### Workarounds\nThere are no effective workarounds, beyond upgrading. Limiting network access to Istiod to the minimal set of clients can help lessen the scope of the vulnerability to some extent.\n\n### References\nMore details can be found in the [Istio Security Bulletin](https://istio.io/latest/news/security/istio-security-2022-003)\n\n### For more information\nIf you have any questions or comments about this advisory, please email us at [istio-security-vulnerability-reports@googlegroups.com](mailto:istio-security-vulnerability-reports@googlegroups.com)\n",
"id": "GHSA-856q-xv3c-7f2f",
"modified": "2022-02-25T15:38:52Z",
"published": "2022-02-23T14:59:08Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/istio/istio/security/advisories/GHSA-856q-xv3c-7f2f"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-23635"
},
{
"type": "WEB",
"url": "https://github.com/istio/istio/commit/5f3b5ed958ae75156f8656fe7b3794f78e94db84"
},
{
"type": "WEB",
"url": "https://github.com/istio/istio"
},
{
"type": "WEB",
"url": "https://istio.io/latest/news/security/istio-security-2022-003"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Unauthenticated control plane denial of service attack in Istio"
}
GHSA-856W-5Q8F-FQ73
Vulnerability from github – Published: 2026-08-28 12:30 – Updated: 2026-08-28 12:30An attacker that holds a token intended for a different purpose can authenticate, because when an OAuth2 token response does not contain a scope claim, the audience claim is used in its place and checked against the configured required scopes. These are different concepts, and the audience claim does not describe what a token is allowed to do. A token that grants no relevant permissions can be accepted because its intended recipient value happens to match a configured scope name, granting access that should have been denied. It also hides an identity provider misconfiguration where scopes are not being issued at all. Ensure the identity provider issues a scope claim for all tokens used with Dovecot, and that configured scope names do not match audience values. Update to non-vulnerable version. No publicly available exploits are known.
{
"affected": [],
"aliases": [
"CVE-2026-73208"
],
"database_specific": {
"cwe_ids": [
"CWE-287"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-28T12:16:31Z",
"severity": "HIGH"
},
"details": "An attacker that holds a token intended for a different purpose can authenticate, because when an OAuth2 token response does not contain a scope claim, the audience claim is used in its place and checked against the configured required scopes. These are different concepts, and the audience claim does not describe what a token is allowed to do. A token that grants no relevant permissions can be accepted because its intended recipient value happens to match a configured scope name, granting access that should have been denied. It also hides an identity provider misconfiguration where scopes are not being issued at all. Ensure the identity provider issues a scope claim for all tokens used with Dovecot, and that configured scope names do not match audience values. Update to non-vulnerable version. No publicly available exploits are known.",
"id": "GHSA-856w-5q8f-fq73",
"modified": "2026-08-28T12:30:26Z",
"published": "2026-08-28T12:30:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-73208"
},
{
"type": "WEB",
"url": "https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
Mitigation
Strategy: Libraries or Frameworks
Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
CAPEC-114: Authentication Abuse
An attacker obtains unauthorized access to an application, service or device either through knowledge of the inherent weaknesses of an authentication mechanism, or by exploiting a flaw in the authentication scheme's implementation. In such an attack an authentication mechanism is functioning but a carefully controlled sequence of events causes the mechanism to grant access to the attacker.
CAPEC-115: Authentication Bypass
An attacker gains access to application, service, or device with the privileges of an authorized or privileged user by evading or circumventing an authentication mechanism. The attacker is therefore able to access protected data without authentication ever having taken place.
CAPEC-151: Identity Spoofing
Identity Spoofing refers to the action of assuming (i.e., taking on) the identity of some other entity (human or non-human) and then using that identity to accomplish a goal. An adversary may craft messages that appear to come from a different principle or use stolen / spoofed authentication credentials.
CAPEC-194: Fake the Source of Data
An adversary takes advantage of improper authentication to provide data or services under a falsified identity. The purpose of using the falsified identity may be to prevent traceability of the provided data or to assume the rights granted to another individual. One of the simplest forms of this attack would be the creation of an email message with a modified "From" field in order to appear that the message was sent from someone other than the actual sender. The root of the attack (in this case the email system) fails to properly authenticate the source and this results in the reader incorrectly performing the instructed action. Results of the attack vary depending on the details of the attack, but common results include privilege escalation, obfuscation of other attacks, and data corruption/manipulation.
CAPEC-22: Exploiting Trust in Client
An attack of this type exploits vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by communicating directly with the server where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
CAPEC-57: Utilizing REST's Trust in the System Resource to Obtain Sensitive Data
This attack utilizes a REST(REpresentational State Transfer)-style applications' trust in the system resources and environment to obtain sensitive data once SSL is terminated.
CAPEC-593: Session Hijacking
This type of attack involves an adversary that exploits weaknesses in an application's use of sessions in performing authentication. The adversary is able to steal or manipulate an active session and use it to gain unathorized access to the application.
CAPEC-633: Token Impersonation
An adversary exploits a weakness in authentication to create an access token (or equivalent) that impersonates a different entity, and then associates a process/thread to that that impersonated token. This action causes a downstream user to make a decision or take action that is based on the assumed identity, and not the response that blocks the adversary.
CAPEC-650: Upload a Web Shell to a Web Server
By exploiting insufficient permissions, it is possible to upload a web shell to a web server in such a way that it can be executed remotely. This shell can have various capabilities, thereby acting as a "gateway" to the underlying web server. The shell might execute at the higher permission level of the web server, providing the ability the execute malicious code at elevated levels.
CAPEC-94: Adversary in the Middle (AiTM)
An adversary targets the communication between two components (typically client and server), in order to alter or obtain data from transactions. A general approach entails the adversary placing themself within the communication channel between the two components.