CVE-2023-48795: The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypas
Noroxi assessment
Priority: Plan (action score 51/100)
- A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
- Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 93.5% (FIRST EPSS); higher than 99.8% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: Azure Linux 3.0 ARM 0.14.0-1, 1.12.12-1, 1.2.0-9; Azure Linux 3.0 x64 0.14.0-1, 1.12.12-1, 1.2.0-9; CBL Mariner 2.0 ARM 0.10.6-1, 1.11.2-7, 1.28.4-4.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Add it to your regular patch cycle. Upgrade to Azure Linux 3.0 ARM 0.14.0-1, 1.12.12-1, 1.2.0-9; Azure Linux 3.0 x64 0.14.0-1, 1.12.12-1, 1.2.0-9; CBL Mariner 2.0 ARM 0.10.6-1, 1.11.2-7, 1.28.4-4 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in chacha20-poly1305@openssh.com and (if CBC is used) the -etm@openssh.com MAC algorithms. This also affects Maverick Synergy Java SSH API before 3.1.0-SNAPSHOT, Dropbear through 2022.83, Ssh before 5.1.1 in Erlang/OTP, PuTTY before 0.80, AsyncSSH before 2.14.2, golang.org/x/crypto before 0.17.0, libssh before 0.10.6, libssh2 through 1.11.0, Thorn Tech SFTP Gateway before 3.4.6, Tera Term before 5.1, Paramiko before 3.4.0, jsch before 0.2.15, SFTPGo before 2.5.6, Netgate pfSense Plus through 23.09.1, Netgate pfSense CE through 2.7.2, HPN-SSH through 18.2.0, ProFTPD before 1.3.8b (and before 1.3.9rc2), ORYX CycloneSSH before 2.3.4, NetSarang XShell 7 before Build 0144, CrushFTP before 10.6.0, ConnectBot SSH library before 2.2.22, Apache MINA sshd through 2.11.0, sshj through 0.37.0, TinySSH through 20230101, trilead-ssh2 6401, LANCOM LCOS and LANconfig, FileZilla before 3.66.4, Nova before 11.8, PKIX-SSH before 14.4, SecureCRT before 9.4.3, Transmit5 before 5.10.4, Win32-OpenSSH before 9.5.0.0p1-Beta, WinSCP before 6.2.2, Bitvise SSH Server before 9.32, Bitvise SSH Client before 9.33, KiTTY through 0.76.1.13, the net-ssh gem 7.2.0 for Ruby, the mscdex ssh2 module before 1.15.0 for Node.js, the thrussh library before 0.35.1 for Rust, and the Russh crate before 0.40.2 for Rust.
- Published
- Dec 18, 2023
- Updated
- Oct 15, 2026
- EPSS
- 93.5% · 99th percentile
- CWE
- CWE-354
Report tools
Action score
51
Plan
Add it to your regular patch cycle.
- CVSS
- 23 / 40 · 5.9 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 28 / 30 · 93.5%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 5.9
- CNA · mitre
- 5.9
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- Proof of concept exists, no weaponized module
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| ssh | ssh | cpe:2.3:a:ssh:ssh |
| openbsd | openssh | cpe:2.3:a:openbsd:openssh |
| putty | putty | cpe:2.3:a:putty:putty |
| filezilla-project | filezilla client | cpe:2.3:a:filezilla-project:filezilla_client |
| apple | macos | cpe:2.3:o:apple:macos |
| panic | transmit 5 | cpe:2.3:a:panic:transmit_5 |
| panic | nova | cpe:2.3:a:panic:nova |
| roumenpetrov | pkixssh | cpe:2.3:a:roumenpetrov:pkixssh |
| winscp | winscp | cpe:2.3:a:winscp:winscp |
| bitvise | ssh client | cpe:2.3:a:bitvise:ssh_client |
| bitvise | ssh server | cpe:2.3:a:bitvise:ssh_server |
| lancom-systems | lcos | cpe:2.3:o:lancom-systems:lcos |
and 56 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- 9bis kittyup to 0.76.1.13 inclusive
- apache sshdup to 2.11.0 inclusive
- apache sshjup to 0.37.0 inclusive
- apple macos14.0 and later · before 14.4
- asyncssh project asyncsshbefore 2.14.2
- bitvise ssh clientbefore 9.33
- bitvise ssh serverbefore 9.32
- connectbot sshlibbefore 2.2.22
- crates thrusshbefore 0.35.1
- crushftp crushftpbefore 10.6.0
- crushftp crushftpup to 10.6.0 inclusive
- debian debian linux10.0
- dropbear ssh project dropbear sshbefore 2022.83
- erlang erlang/otpbefore 22.3.4.27
- erlang erlang/otp26.0 and later · before 26.2.1
- erlang erlang/otp25.0 and later · before 25.3.2.8
- erlang erlang/otp24.0 and later · before 24.3.4.15
- erlang erlang/otp23.0 and later · before 23.3.4.20
- fedoraproject fedora38
- fedoraproject fedora39
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | libssh | before 0.9.6-13.el8_9 | 0.9.6-13.el8_9 |
| AlmaLinux:8 | libssh-config | before 0.9.6-13.el8_9 | 0.9.6-13.el8_9 |
| AlmaLinux:8 | libssh-devel | before 0.9.6-13.el8_9 | 0.9.6-13.el8_9 |
| AlmaLinux:8 | openssh | before 8.0p1-19.el8_9.2 | 8.0p1-19.el8_9.2 |
| AlmaLinux:8 | openssh-askpass | before 8.0p1-19.el8_9.2 | 8.0p1-19.el8_9.2 |
| AlmaLinux:8 | openssh-cavs | before 8.0p1-19.el8_9.2 | 8.0p1-19.el8_9.2 |
| AlmaLinux:8 | openssh-clients | before 8.0p1-19.el8_9.2 | 8.0p1-19.el8_9.2 |
| AlmaLinux:8 | openssh-keycat | before 8.0p1-19.el8_9.2 | 8.0p1-19.el8_9.2 |
| AlmaLinux:8 | openssh-ldap | before 8.0p1-19.el8_9.2 | 8.0p1-19.el8_9.2 |
| AlmaLinux:8 | openssh-server | before 8.0p1-19.el8_9.2 | 8.0p1-19.el8_9.2 |
| AlmaLinux:8 | pam_ssh_agent_auth | before 0.10.3-7.19.el8_9.2 | 0.10.3-7.19.el8_9.2 |
| AlmaLinux:9 | buildah | before 1:1.31.4-1.el9_3 | 1:1.31.4-1.el9_3 |
| AlmaLinux:9 | buildah-tests | before 1:1.31.4-1.el9_3 | 1:1.31.4-1.el9_3 |
| AlmaLinux:9 | openssh | before 8.7p1-34.el9_3.3 | 8.7p1-34.el9_3.3 |
| AlmaLinux:9 | openssh-askpass | before 8.7p1-34.el9_3.3 | 8.7p1-34.el9_3.3 |
| AlmaLinux:9 | openssh-clients | before 8.7p1-34.el9_3.3 | 8.7p1-34.el9_3.3 |
| AlmaLinux:9 | openssh-keycat | before 8.7p1-34.el9_3.3 | 8.7p1-34.el9_3.3 |
| AlmaLinux:9 | openssh-server | before 8.7p1-34.el9_3.3 | 8.7p1-34.el9_3.3 |
| AlmaLinux:9 | pam_ssh_agent_auth | before 0.10.4-5.34.el9_3.3 | 0.10.4-5.34.el9_3.3 |
| Alpine:v3.16 | dropbear | before 2022.82-r2 | 2022.82-r2 |
| Alpine:v3.16 | libssh2 | before 1.11.0-r0 | 1.11.0-r0 |
| Alpine:v3.16 | openssh | before 9.0_p1-r5 | 9.0_p1-r5 |
| Alpine:v3.16 | putty | before 0.80-r0 | 0.80-r0 |
| Alpine:v3.17 | dropbear | before 2022.83-r1 | 2022.83-r1 |
+96
Same product
ssh: all recordsOther highest-scoring records for the same primary product.
- CVE-2001-0144CORE SDI SSH1 CRC-32 compensation attack detector allows remote attackers to execute arbitrary commands on an SSH server or client via an in50Plan
- CVE-1999-0248A race condition in the authentication agent mechanism of sshd 1.2.17 allows an attacker to steal another user's credentials.40Plan
- CVE-1999-0013Stolen credentials from SSH clients via ssh-agent program, allowing other local users to access remote accounts belonging to the ssh-agent u33Monitor
Published before and after this one in the same product
- ← EarlierCVE-2001-0471Jun 27, 2001 · SSH daemon version 1 (aka SSHD-1 or SSH-1) 1.2.30 and earlier does not log repeated login attempts, which could allow remote attackers to co32Monitor
- ← EarlierCVE-2001-0572Aug 22, 2001 · The SSH protocols 1 and 2 (aka SSH-2) as implemented in OpenSSH and other packages have various weaknesses which can allow a remote attacker32Monitor
- ← EarlierCVE-2002-1715Dec 31, 2002 · SSH 1 through 3, and possibly other versions, allows local users to bypass restricted shells such as rbash or rksh by uploading a script to 28Monitor
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 |
|---|---|---|
| Azure Linux 3.0 ARM | 0.14.0-1 · docker-buildx | Microsoft (MSRC) |
| Azure Linux 3.0 ARM | 1.12.12-1 · cert-manager | Microsoft (MSRC) |
| Azure Linux 3.0 ARM | 1.2.0-9 · kubevirt | Microsoft (MSRC) |
| Azure Linux 3.0 ARM | 1.30.1-1 · kubernetes | Microsoft (MSRC) |
| Azure Linux 3.0 x64 | 0.14.0-1 · docker-buildx | Microsoft (MSRC) |
| Azure Linux 3.0 x64 | 1.12.12-1 · cert-manager | Microsoft (MSRC) |
| Azure Linux 3.0 x64 | 1.2.0-9 · kubevirt | Microsoft (MSRC) |
| Azure Linux 3.0 x64 | 1.30.1-1 · kubernetes | Microsoft (MSRC) |
| CBL Mariner 2.0 ARM | 0.10.6-1 · libssh | Microsoft (MSRC) |
| CBL Mariner 2.0 ARM | 1.11.2-7 · cert-manager | Microsoft (MSRC) |
| CBL Mariner 2.0 ARM | 1.28.4-4 · kubernetes | Microsoft (MSRC) |
| CBL Mariner 2.0 ARM | 25.2-2 · erlang | Microsoft (MSRC) |
| CBL Mariner 2.0 x64 | 0.10.6-1 · libssh | Microsoft (MSRC) |
| CBL Mariner 2.0 x64 | 1.11.2-7 · cert-manager | Microsoft (MSRC) |
| CBL Mariner 2.0 x64 | 1.28.4-4 · kubernetes | Microsoft (MSRC) |
| CBL Mariner 2.0 x64 | 25.2-2 · erlang | Microsoft (MSRC) |
| almalinux:buildah | 1:1.31.4-1.el9_3 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:libssh | 0.9.6-13.el8_9 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:libssh-config | 0.9.6-13.el8_9 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:libssh-devel | 0.9.6-13.el8_9 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:openssh | 8.0p1-19.el8_9.2 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:openssh-askpass | 8.0p1-19.el8_9.2 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:openssh-cavs | 8.0p1-19.el8_9.2 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:openssh-clients | 8.0p1-19.el8_9.2 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:openssh-keycat | 8.0p1-19.el8_9.2 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:openssh-ldap | 8.0p1-19.el8_9.2 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:openssh-server | 8.0p1-19.el8_9.2 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:pam_ssh_agent_auth | 0.10.3-7.19.el8_9.2 · AlmaLinux:8 | Package registry (OSV) |
| alpine:dropbear | 2022.82-r2 · Alpine:v3.16 | Package registry (OSV) |
| alpine:libssh2 | 1.11.0-r0 · Alpine:v3.16 | Package registry (OSV) |
+67
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Nuclei detection template ×1
- Proof-of-concept repository on GitHub ×5
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Nuclei detection template | Nuclei template CVE-2023-48795 | — |
| Proof-of-concept repository on GitHub | stars:14 | 2025-01-08 |
| Proof-of-concept repository on GitHub | stars:0 | 2025-05-23 |
| Proof-of-concept repository on GitHub | stars:2 | 2026-05-21 |
| Proof-of-concept repository on GitHub | stars:1 | 2026-06-08 |
| Proof-of-concept repository on GitHub | stars:0 | 2026-10-25 |
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.
- Published
- First PoC+386 d
- TodayOct 28, 2026+1045 d
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.
- git.libssh.orgpatch
- NixOS/nixpkgsPR 275249
- TeraTermProject/teratermcommit 7279fbd
- connectbot/sshlibcommit 5c8b534
- connectbot/sshlibcompare 2.2.21...2.2
- golang/cryptocommit 9d2ee97
- jtesta/ssh-auditcommit 8e972c5
- libssh2/libssh2PR 1291
- mscdex/ssh2commit 97b223f
- mwiede/jschcompare jsch-0.2.14.
- mwiede/jschPR 461
- openssh/openssh-portablecommit master
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).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-23-0719 · Dec 20, 2023(OpenSSH Güvenlik Bildirimi)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- none
- Integrity
- high · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- High
- Availability impact
- None
Weakness class (CWE)
CWE-354 · Improper Validation of Integrity Check ValueCVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
nvd-primary
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)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (19 more)Show less
- seclists.org/fulldisclosure/2024/Mar/21
- www.openwall.com/lists/oss-security/2023/12/18/3
- www.openwall.com/lists/oss-security/2023/12/19/5
- www.openwall.com/lists/oss-security/2023/12/20/3
- www.openwall.com/lists/oss-security/2024/03/06/3
- www.openwall.com/lists/oss-security/2024/04/17/8
- access.redhat.com/security/cve/cve-2023-48795
- arstechnica.com/security/2023/12/hackers-can-break-ssh-channel-integrity-using-novel-data-corruption-attack/
- bugs.gentoo.org/920280
- bugzilla.redhat.com/show_bug.cgi?id=2254210
- bugzilla.suse.com/show_bug.cgi?id=1217950
- crates.io/crates/thrussh/versions
- filezilla-project.org/versions.php
- forum.netgate.com/topic/184941/terrapin-ssh-attack
- git.libssh.org/projects/libssh.git/commit/?h=stable-0.10&id=10e09e273f69e149389b3e0e5d44b8c221c2e7f6
- github.com/NixOS/nixpkgs/pull/275249
- github.com/PowerShell/Win32-OpenSSH/issues/2189
- github.com/PowerShell/Win32-OpenSSH/releases/tag/v9.5.0.0p1-Beta
- github.com/TeraTermProject/teraterm/commit/7279fbd6ef4d0c8bdd6a90af4ada2899d786eec0
Vendor advisories and official records. Exploit/PoC links are deliberately left out.