431 lines
22 KiB
JSON
431 lines
22 KiB
JSON
{
|
||
"dataType": "CVE_RECORD",
|
||
"dataVersion": "5.2",
|
||
"cveMetadata": {
|
||
"cveId": "CVE-2026-23943",
|
||
"assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
|
||
"state": "PUBLISHED",
|
||
"assignerShortName": "EEF",
|
||
"dateReserved": "2026-01-19T14:23:14.343Z",
|
||
"datePublished": "2026-03-13T09:11:57.794Z",
|
||
"dateUpdated": "2026-11-11T19:44:14.524Z"
|
||
},
|
||
"containers": {
|
||
"cna": {
|
||
"affected": [
|
||
{
|
||
"cpes": [
|
||
"cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"
|
||
],
|
||
"defaultStatus": "unaffected",
|
||
"modules": [
|
||
"ssh_transport"
|
||
],
|
||
"packageName": "otp",
|
||
"packageURL": "pkg:software-id/erlang.org/otp",
|
||
"product": "OTP",
|
||
"programFiles": [
|
||
"lib/ssh/src/ssh_transport.erl"
|
||
],
|
||
"programRoutines": [
|
||
{
|
||
"name": "ssh_transport:decompress/2"
|
||
},
|
||
{
|
||
"name": "ssh_transport:handle_packet_part/4"
|
||
}
|
||
],
|
||
"vendor": "Erlang",
|
||
"versions": [
|
||
{
|
||
"changes": [
|
||
{
|
||
"at": "26.2.5.18",
|
||
"status": "unaffected"
|
||
},
|
||
{
|
||
"at": "27.3.4.9",
|
||
"status": "unaffected"
|
||
},
|
||
{
|
||
"at": "28.4.1",
|
||
"status": "unaffected"
|
||
}
|
||
],
|
||
"lessThan": "*",
|
||
"status": "affected",
|
||
"version": "17.0",
|
||
"versionType": "otp"
|
||
}
|
||
]
|
||
},
|
||
{
|
||
"cpes": [
|
||
"cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"
|
||
],
|
||
"defaultStatus": "unaffected",
|
||
"modules": [
|
||
"ssh_transport"
|
||
],
|
||
"packageName": "ssh",
|
||
"packageURL": "pkg:otp/ssh?repository_url=https:%2F%2Fgithub.com%2Ferlang%2Fotp&vcs_url=git%2Bhttps:%2F%2Fgithub.com%2Ferlang%2Fotp.git",
|
||
"product": "OTP",
|
||
"programFiles": [
|
||
"src/ssh_transport.erl"
|
||
],
|
||
"programRoutines": [
|
||
{
|
||
"name": "ssh_transport:decompress/2"
|
||
},
|
||
{
|
||
"name": "ssh_transport:handle_packet_part/4"
|
||
}
|
||
],
|
||
"repo": "https://github.com/erlang/otp",
|
||
"vendor": "Erlang",
|
||
"versions": [
|
||
{
|
||
"changes": [
|
||
{
|
||
"at": "5.1.4.14",
|
||
"status": "unaffected"
|
||
},
|
||
{
|
||
"at": "5.2.11.6",
|
||
"status": "unaffected"
|
||
},
|
||
{
|
||
"at": "5.5.1",
|
||
"status": "unaffected"
|
||
}
|
||
],
|
||
"lessThan": "*",
|
||
"status": "affected",
|
||
"version": "3.0.1",
|
||
"versionType": "otp"
|
||
}
|
||
]
|
||
},
|
||
{
|
||
"collectionURL": "https://github.com",
|
||
"cpes": [
|
||
"cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"
|
||
],
|
||
"defaultStatus": "unaffected",
|
||
"modules": [
|
||
"ssh_transport"
|
||
],
|
||
"packageName": "erlang/otp",
|
||
"packageURL": "pkg:github/erlang/otp",
|
||
"product": "OTP",
|
||
"programFiles": [
|
||
"lib/ssh/src/ssh_transport.erl"
|
||
],
|
||
"programRoutines": [
|
||
{
|
||
"name": "ssh_transport:decompress/2"
|
||
},
|
||
{
|
||
"name": "ssh_transport:handle_packet_part/4"
|
||
}
|
||
],
|
||
"repo": "https://github.com/erlang/otp",
|
||
"vendor": "Erlang",
|
||
"versions": [
|
||
{
|
||
"changes": [
|
||
{
|
||
"at": "0c1c04b191f6ab940e8fcfabce39eb5a8a6440a4",
|
||
"status": "unaffected"
|
||
},
|
||
{
|
||
"at": "93073c3bd338c60cd2bae715ce6a1d4ffc1a8fd3",
|
||
"status": "unaffected"
|
||
},
|
||
{
|
||
"at": "43a87b949bdff12d629a8c34146711d9da93b1b1",
|
||
"status": "unaffected"
|
||
}
|
||
],
|
||
"lessThan": "*",
|
||
"status": "affected",
|
||
"version": "07b8f441ca711f9812fad9e9115bab3c3aa92f79",
|
||
"versionType": "git"
|
||
}
|
||
]
|
||
}
|
||
],
|
||
"configurations": [
|
||
{
|
||
"lang": "en",
|
||
"supportingMedia": [
|
||
{
|
||
"base64": false,
|
||
"type": "text/html",
|
||
"value": "<p>The SSH server or client must advertise <code>zlib</code> or <code>zlib@openssh.com</code> compression. Both are enabled by default. With <code>zlib</code>, the attack is pre-authentication; with <code>zlib@openssh.com</code>, authentication is required first.</p>"
|
||
},
|
||
{
|
||
"base64": false,
|
||
"type": "text/markdown",
|
||
"value": "The SSH server or client must advertise `zlib` or `zlib@openssh.com` compression. Both are enabled by default. With `zlib`, the attack is pre-authentication; with `zlib@openssh.com`, authentication is required first."
|
||
}
|
||
],
|
||
"value": "The SSH server or client must advertise zlib or zlib@openssh.com compression. Both are enabled by default. With zlib, the attack is pre-authentication; with zlib@openssh.com, authentication is required first."
|
||
}
|
||
],
|
||
"cpeApplicability": [
|
||
{
|
||
"nodes": [
|
||
{
|
||
"cpeMatch": [
|
||
{
|
||
"criteria": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*",
|
||
"versionEndExcluding": "26.2.5.18",
|
||
"versionStartIncluding": "17.0",
|
||
"vulnerable": true
|
||
},
|
||
{
|
||
"criteria": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*",
|
||
"versionEndExcluding": "27.3.4.9",
|
||
"versionStartIncluding": "27.0",
|
||
"vulnerable": true
|
||
},
|
||
{
|
||
"criteria": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*",
|
||
"versionEndExcluding": "28.4.1",
|
||
"versionStartIncluding": "28.0",
|
||
"vulnerable": true
|
||
}
|
||
],
|
||
"negate": false,
|
||
"operator": "OR"
|
||
}
|
||
],
|
||
"operator": "AND"
|
||
}
|
||
],
|
||
"credits": [
|
||
{
|
||
"lang": "en",
|
||
"type": "finder",
|
||
"value": "Igor Morgenstern / Aisle Research"
|
||
},
|
||
{
|
||
"lang": "en",
|
||
"type": "remediation developer",
|
||
"value": "Michał Wąsowski"
|
||
},
|
||
{
|
||
"lang": "en",
|
||
"type": "remediation reviewer",
|
||
"value": "Jakub Witczak"
|
||
}
|
||
],
|
||
"datePublic": "2026-03-13T09:11:57.000Z",
|
||
"descriptions": [
|
||
{
|
||
"lang": "en",
|
||
"supportingMedia": [
|
||
{
|
||
"base64": false,
|
||
"type": "text/html",
|
||
"value": "<p>Improper Handling of Highly Compressed Data (Compression Bomb) vulnerability in Erlang OTP ssh (ssh_transport modules) allows Denial of Service via Resource Depletion.</p>\n<p>The SSH transport layer advertises legacy zlib compression by default and inflates attacker-controlled payloads pre-authentication without any size limit, enabling reliable memory exhaustion DoS.</p>\n<p>Two compression algorithms are affected:</p>\n<ul>\n<li><strong><code>zlib</code>:</strong> Activates immediately after key exchange, enabling unauthenticated attacks</li>\n<li><strong><code>zlib@openssh.com</code>:</strong> Activates post-authentication, enabling authenticated attacks</li>\n</ul>\n<p>Each SSH packet can decompress ~255 MB from 256 KB of wire data (1029:1 amplification ratio). Multiple packets can rapidly exhaust available memory, causing OOM kills in memory-constrained environments.</p>\n<p>This vulnerability is associated with program files <code>lib/ssh/src/ssh_transport.erl</code> and program routines <code>ssh_transport:decompress/2</code>, <code>ssh_transport:handle_packet_part/4</code>.</p>\n<p>This issue affects OTP from OTP 17.0 before OTP 26.2.5.18, OTP 27.3.4.9, and OTP 28.4.1, corresponding to ssh from 3.0.1 before 5.1.4.14, 5.2.11.6, and 5.5.1.</p>"
|
||
},
|
||
{
|
||
"base64": false,
|
||
"type": "text/markdown",
|
||
"value": "Improper Handling of Highly Compressed Data (Compression Bomb) vulnerability in Erlang OTP ssh (ssh_transport modules) allows Denial of Service via Resource Depletion.\n\nThe SSH transport layer advertises legacy zlib compression by default and inflates attacker-controlled payloads pre-authentication without any size limit, enabling reliable memory exhaustion DoS.\n\nTwo compression algorithms are affected:\n\n* **`zlib`:** Activates immediately after key exchange, enabling unauthenticated attacks\n* **`zlib@openssh.com`:** Activates post-authentication, enabling authenticated attacks\n\nEach SSH packet can decompress ~255 MB from 256 KB of wire data (1029:1 amplification ratio). Multiple packets can rapidly exhaust available memory, causing OOM kills in memory-constrained environments.\n\nThis vulnerability is associated with program files `lib/ssh/src/ssh_transport.erl` and program routines `ssh_transport:decompress/2`, `ssh_transport:handle_packet_part/4`.\n\nThis issue affects OTP from OTP 17.0 before OTP 26.2.5.18, OTP 27.3.4.9, and OTP 28.4.1, corresponding to ssh from 3.0.1 before 5.1.4.14, 5.2.11.6, and 5.5.1."
|
||
}
|
||
],
|
||
"value": "Improper Handling of Highly Compressed Data (Compression Bomb) vulnerability in Erlang OTP ssh (ssh_transport modules) allows Denial of Service via Resource Depletion.\n\nThe SSH transport layer advertises legacy zlib compression by default and inflates attacker-controlled payloads pre-authentication without any size limit, enabling reliable memory exhaustion DoS.\n\nTwo compression algorithms are affected:\n\n* zlib: Activates immediately after key exchange, enabling unauthenticated attacks\n* zlib@openssh.com: Activates post-authentication, enabling authenticated attacks\n\nEach SSH packet can decompress ~255 MB from 256 KB of wire data (1029:1 amplification ratio). Multiple packets can rapidly exhaust available memory, causing OOM kills in memory-constrained environments.\n\nThis vulnerability is associated with program files lib/ssh/src/ssh_transport.erl and program routines ssh_transport:decompress/2, ssh_transport:handle_packet_part/4.\n\nThis issue affects OTP from OTP 17.0 before OTP 26.2.5.18, OTP 27.3.4.9, and OTP 28.4.1, corresponding to ssh from 3.0.1 before 5.1.4.14, 5.2.11.6, and 5.5.1."
|
||
}
|
||
],
|
||
"impacts": [
|
||
{
|
||
"capecId": "CAPEC-130",
|
||
"descriptions": [
|
||
{
|
||
"lang": "en",
|
||
"value": "CAPEC-130 Excessive Allocation"
|
||
}
|
||
]
|
||
},
|
||
{
|
||
"capecId": "CAPEC-490",
|
||
"descriptions": [
|
||
{
|
||
"lang": "en",
|
||
"value": "CAPEC-490 Amplification"
|
||
}
|
||
]
|
||
}
|
||
],
|
||
"metrics": [
|
||
{
|
||
"cvssV4_0": {
|
||
"Automatable": "NOT_DEFINED",
|
||
"Recovery": "NOT_DEFINED",
|
||
"Safety": "NOT_DEFINED",
|
||
"attackComplexity": "LOW",
|
||
"attackRequirements": "NONE",
|
||
"attackVector": "NETWORK",
|
||
"baseScore": 6.9,
|
||
"baseSeverity": "MEDIUM",
|
||
"privilegesRequired": "NONE",
|
||
"providerUrgency": "NOT_DEFINED",
|
||
"subAvailabilityImpact": "NONE",
|
||
"subConfidentialityImpact": "NONE",
|
||
"subIntegrityImpact": "NONE",
|
||
"userInteraction": "NONE",
|
||
"valueDensity": "NOT_DEFINED",
|
||
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
|
||
"version": "4.0",
|
||
"vulnAvailabilityImpact": "LOW",
|
||
"vulnConfidentialityImpact": "NONE",
|
||
"vulnIntegrityImpact": "NONE",
|
||
"vulnerabilityResponseEffort": "NOT_DEFINED"
|
||
},
|
||
"format": "CVSS",
|
||
"scenarios": [
|
||
{
|
||
"lang": "en",
|
||
"value": "GENERAL"
|
||
}
|
||
]
|
||
}
|
||
],
|
||
"problemTypes": [
|
||
{
|
||
"descriptions": [
|
||
{
|
||
"cweId": "CWE-409",
|
||
"description": "CWE-409 Improper Handling of Highly Compressed Data (Data Amplification)",
|
||
"lang": "en",
|
||
"type": "CWE"
|
||
}
|
||
]
|
||
}
|
||
],
|
||
"providerMetadata": {
|
||
"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
|
||
"shortName": "EEF",
|
||
"dateUpdated": "2026-11-11T19:44:14.524Z"
|
||
},
|
||
"references": [
|
||
{
|
||
"name": "Pre-auth SSH DoS via unbounded zlib inflate",
|
||
"tags": [
|
||
"vendor-advisory",
|
||
"related"
|
||
],
|
||
"url": "https://github.com/erlang/otp/security/advisories/GHSA-c836-qprm-jw9r"
|
||
},
|
||
{
|
||
"name": "EEF CNA record for CVE-2026-23943",
|
||
"tags": [
|
||
"related"
|
||
],
|
||
"url": "https://cna.erlef.org/cves/CVE-2026-23943.html"
|
||
},
|
||
{
|
||
"name": "OSV record EEF-CVE-2026-23943",
|
||
"tags": [
|
||
"related"
|
||
],
|
||
"url": "https://osv.dev/vulnerability/EEF-CVE-2026-23943"
|
||
},
|
||
{
|
||
"name": "Erlang/OTP version ordering",
|
||
"tags": [
|
||
"x_version-scheme"
|
||
],
|
||
"url": "https://www.erlang.org/doc/system/versions.html#order-of-versions"
|
||
},
|
||
{
|
||
"name": "Introducing commit 07b8f44 in erlang/otp",
|
||
"tags": [
|
||
"related"
|
||
],
|
||
"url": "https://github.com/erlang/otp/commit/07b8f441ca711f9812fad9e9115bab3c3aa92f79"
|
||
},
|
||
{
|
||
"name": "Fix commit 0c1c04b in erlang/otp",
|
||
"tags": [
|
||
"patch"
|
||
],
|
||
"url": "https://github.com/erlang/otp/commit/0c1c04b191f6ab940e8fcfabce39eb5a8a6440a4"
|
||
},
|
||
{
|
||
"name": "Fix commit 93073c3 in erlang/otp",
|
||
"tags": [
|
||
"patch"
|
||
],
|
||
"url": "https://github.com/erlang/otp/commit/93073c3bd338c60cd2bae715ce6a1d4ffc1a8fd3"
|
||
},
|
||
{
|
||
"name": "Fix commit 43a87b9 in erlang/otp",
|
||
"tags": [
|
||
"patch"
|
||
],
|
||
"url": "https://github.com/erlang/otp/commit/43a87b949bdff12d629a8c34146711d9da93b1b1"
|
||
}
|
||
],
|
||
"source": {
|
||
"discovery": "EXTERNAL"
|
||
},
|
||
"title": "Pre-auth SSH DoS via unbounded zlib inflate",
|
||
"workarounds": [
|
||
{
|
||
"lang": "en",
|
||
"supportingMedia": [
|
||
{
|
||
"base64": false,
|
||
"type": "text/html",
|
||
"value": "<p><strong>Best workaround - Disable all compression:</strong></p>\n<pre><code class=\"language-erlang\">{preferred_algorithms, [{compression, ['none']}]}\n</code></pre>\n<p><strong>Alternative mitigations (less secure):</strong></p>\n<ul>\n<li>\n<p>Disable only pre-auth zlib compression (authenticated users can still exploit via <code>zlib@openssh.com</code>):</p>\n<pre><code class=\"language-erlang\">{modify_algorithms, [{rm, [{compression, ['zlib']}]}]}\n</code></pre>\n</li>\n<li>\n<p>Limit concurrent sessions (reduces attack surface but does not prevent exploitation):</p>\n<pre><code class=\"language-erlang\">{max_sessions, N} % Cap total concurrent sessions (default is infinity)\n</code></pre>\n</li>\n</ul>"
|
||
},
|
||
{
|
||
"base64": false,
|
||
"type": "text/markdown",
|
||
"value": "**Best workaround - Disable all compression:**\n\n```erlang\n{preferred_algorithms, [{compression, ['none']}]}\n```\n\n**Alternative mitigations (less secure):**\n\n* Disable only pre-auth zlib compression (authenticated users can still exploit via `zlib@openssh.com`):\n\n ```erlang\n {modify_algorithms, [{rm, [{compression, ['zlib']}]}]}\n ```\n\n* Limit concurrent sessions (reduces attack surface but does not prevent exploitation):\n\n ```erlang\n {max_sessions, N} % Cap total concurrent sessions (default is infinity)\n ```"
|
||
}
|
||
],
|
||
"value": "Best workaround - Disable all compression:\n\n{preferred_algorithms, [{compression, ['none']}]}\n\nAlternative mitigations (less secure):\n\n* Disable only pre-auth zlib compression (authenticated users can still exploit via zlib@openssh.com):\n{modify_algorithms, [{rm, [{compression, ['zlib']}]}]}\n* Limit concurrent sessions (reduces attack surface but does not prevent exploitation):\n{max_sessions, N} % Cap total concurrent sessions (default is infinity)"
|
||
}
|
||
]
|
||
},
|
||
"adp": [
|
||
{
|
||
"metrics": [
|
||
{
|
||
"other": {
|
||
"type": "ssvc",
|
||
"content": {
|
||
"timestamp": "2026-03-13T16:01:40.898658Z",
|
||
"id": "CVE-2026-23943",
|
||
"options": [
|
||
{
|
||
"Exploitation": "none"
|
||
},
|
||
{
|
||
"Automatable": "yes"
|
||
},
|
||
{
|
||
"Technical Impact": "partial"
|
||
}
|
||
],
|
||
"role": "CISA Coordinator",
|
||
"version": "2.0.3"
|
||
}
|
||
}
|
||
}
|
||
],
|
||
"title": "CISA ADP Vulnrichment",
|
||
"providerMetadata": {
|
||
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
|
||
"shortName": "CISA-ADP",
|
||
"dateUpdated": "2026-03-13T16:01:48.609Z"
|
||
}
|
||
}
|
||
]
|
||
}
|
||
} |