The monitor component in sshd in OpenSSH before 7.0 on non-OpenBSD platforms accepts extraneous username data in MONITOR_REQ_PAM_INIT_CTX re
The monitor component in sshd in OpenSSH before 7.0 on non-OpenBSD platforms accepts extraneous username data in MONITOR_REQ_PAM_INIT_CTX requests, which allows local users to conduct impersonation attacks by leveraging any SSH login access in conjunction with control of the sshd uid to send a crafted MONITOR_REQ_PWNAM request, related to monitor.c and monitor_wrap.c.
- Published
- Aug 23, 2015
- Updated
- Jun 16, 2026
- EPSS
- 0.4% · 30th percentile
- CWE
- CWE-20
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Report tools
Action score
25
Monitor
Low priority for now.
- CVSS
- 25 / 40 · 6.4 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
Affected systems
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- apple mac os xup to 10.11.0 inclusive
- openbsd opensshup to 6.9 inclusive
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | openssh | before 1:6.9p1-1 | 1:6.9p1-1 |
| Debian:8 | openssh | before 1:6.7p1-5+deb8u6 | 1:6.7p1-5+deb8u6 |
| Red Hat:enterprise_linux:6::client | openssh | before 0:5.3p1-117.el6 | 0:5.3p1-117.el6 |
| Red Hat:enterprise_linux:6::client | openssh-askpass | before 0:5.3p1-117.el6 | 0:5.3p1-117.el6 |
| Red Hat:enterprise_linux:6::client | openssh-clients | before 0:5.3p1-117.el6 | 0:5.3p1-117.el6 |
| Red Hat:enterprise_linux:6::client | openssh-debuginfo | before 0:5.3p1-117.el6 | 0:5.3p1-117.el6 |
| Red Hat:enterprise_linux:6::client | openssh-ldap | before 0:5.3p1-117.el6 | 0:5.3p1-117.el6 |
| Red Hat:enterprise_linux:6::client | openssh-server | before 0:5.3p1-117.el6 | 0:5.3p1-117.el6 |
| Red Hat:enterprise_linux:6::client | pam_ssh_agent_auth | before 0:0.9.3-117.el6 | 0:0.9.3-117.el6 |
| Red Hat:enterprise_linux:7::client | openssh | before 0:6.6.1p1-22.el7 | 0:6.6.1p1-22.el7 |
| Red Hat:enterprise_linux:7::client | openssh-askpass | before 0:6.6.1p1-22.el7 | 0:6.6.1p1-22.el7 |
| Red Hat:enterprise_linux:7::client | openssh-clients | before 0:6.6.1p1-22.el7 | 0:6.6.1p1-22.el7 |
| Red Hat:enterprise_linux:7::client | openssh-debuginfo | before 0:6.6.1p1-22.el7 | 0:6.6.1p1-22.el7 |
| Red Hat:enterprise_linux:7::client | openssh-keycat | before 0:6.6.1p1-22.el7 | 0:6.6.1p1-22.el7 |
| Red Hat:enterprise_linux:7::client | openssh-ldap | before 0:6.6.1p1-22.el7 | 0:6.6.1p1-22.el7 |
| Red Hat:enterprise_linux:7::client | openssh-server | before 0:6.6.1p1-22.el7 | 0:6.6.1p1-22.el7 |
| Red Hat:enterprise_linux:7::client | openssh-server-sysvinit | before 0:6.6.1p1-22.el7 | 0:6.6.1p1-22.el7 |
| Red Hat:enterprise_linux:7::client | pam_ssh_agent_auth | before 0:0.9.3-9.22.el7 | 0:0.9.3-9.22.el7 |
| SUSE:Linux Enterprise Desktop 11 SP3 | openssh | before 6.2p2-0.21.1 | 6.2p2-0.21.1 |
| SUSE:Linux Enterprise Desktop 11 SP3 | openssh-askpass-gnome | before 6.2p2-0.21.3 | 6.2p2-0.21.3 |
| SUSE:Linux Enterprise Desktop 11 SP4 | openssh | before 6.6p1-13.1 | 6.6p1-13.1 |
| SUSE:Linux Enterprise Desktop 11 SP4 | openssh-askpass-gnome | before 6.6p1-13.3 | 6.6p1-13.3 |
| SUSE:Linux Enterprise Desktop 12 | openssh | before 6.6p1-29.1 | 6.6p1-29.1 |
| SUSE:Linux Enterprise Desktop 12 | openssh-askpass-gnome | before 6.6p1-29.1 | 6.6p1-29.1 |
Same product
openbsd: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-38408The PKCS#11 feature in ssh-agent in OpenSSH before 9.3p2 has an insufficiently trustworthy search path, leading to remote code execution if 63This week
- CVE-2023-25136OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during options.kex_algorithms handling.53Plan
- CVE-2018-15473OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying bailout for an invalid authenticating user until after 51Plan
- CVE-2016-6210sshd in OpenSSH before 7.3, when SHA256 or SHA512 are used for user password hashing, uses BLOWFISH hashing on a static password when the us50Plan
- CVE-2016-6515The auth_password function in auth-passwd.c in sshd in OpenSSH before 7.3 does not limit password lengths for password authentication, which48Plan
- CVE-2002-0640Buffer overflow in sshd in OpenSSH 2.3.1 through 3.3 may allow remote attackers to execute arbitrary code via a large number of responses du48Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:openssh | 1:6.9p1-1 · Debian:12 | Package registry (OSV) |
| red hat:openssh | 0:6.6.1p1-22.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:openssh-askpass | 0:6.6.1p1-22.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:openssh-clients | 0:6.6.1p1-22.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:openssh-debuginfo | 0:6.6.1p1-22.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:openssh-keycat | 0:6.6.1p1-22.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:openssh-ldap | 0:6.6.1p1-22.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:openssh-server | 0:6.6.1p1-22.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:openssh-server-sysvinit | 0:6.6.1p1-22.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:pam_ssh_agent_auth | 0:0.9.3-9.22.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| suse:openssh | 6.6p1-29.1 · SUSE:Linux Enterprise Desktop 12 | Package registry (OSV) |
| suse:openssh-askpass-gnome | 6.6p1-29.1 · SUSE:Linux Enterprise Desktop 12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- Administrator privileges are required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- High
- Privileges required
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- lists.apple.com/archives/security-announce/2015/Oct/msg00005.html
- lists.fedoraproject.org/pipermail/package-announce/2015-August/165170.html
- lists.opensuse.org/opensuse-security-announce/2015-09/msg00017.html
- rhn.redhat.com/errata/RHSA-2016-0741.html
- seclists.org/fulldisclosure/2015/Aug/54
- www.openssh.com/txt/release-7.0
- www.openwall.com/lists/oss-security/2015/08/22/1
- www.oracle.com/technetwork/topics/security/bulletinjan2016-2867206.html
- www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
- www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
- www.securityfocus.com/bid/76317
- cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf
- github.com/openssh/openssh-portable/commit/d4697fe9a28dab7255c60433e4dd23cf7fce8a8b
- lists.debian.org/debian-lts-announce/2018/09/msg00010.html
- security.gentoo.org/glsa/201512-04
- security.netapp.com/advisory/ntap-20180201-0002/
- support.apple.com/HT205375
- www.broadcom.com/support/fibre-channel-networking/security-advisories/brocade-security-advisory-2019-766
Vendor advisories and official records. Exploit/PoC links are deliberately left out.