Implementations of SSH version 1.5, including (1) OpenSSH up to version 2.3.0, (2) AppGate, and (3) ssh-1 up to version 1.2.31, in certain c
Implementations of SSH version 1.5, including (1) OpenSSH up to version 2.3.0, (2) AppGate, and (3) ssh-1 up to version 1.2.31, in certain configurations, allow a remote attacker to decrypt and/or alter traffic via a "Bleichenbacher attack" on PKCS#1 version 1.5.
- Published
- Jun 27, 2001
- Updated
- Jun 16, 2026
- EPSS
- 2.5% · 84th percentile
- CWE
- CWE-310
Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.
Report tools
Action score
17
Monitor
Low priority for now.
- CVSS
- 16 / 40 · 4.0 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.5%
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; 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 helpAffected systems
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- openbsd openssh1.2.3
- openbsd openssh2.1
- openbsd openssh2.1.1
- ssh sshup to 1.2.31 inclusive
Same product
ssh: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-48795The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypas51Plan
- 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
- CVE-2001-0572The SSH protocols 1 and 2 (aka SSH-2) as implemented in OpenSSH and other packages have various weaknesses which can allow a remote attacker32Monitor
- CVE-2001-0471SSH 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
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
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.
No commit or PR link among the references.
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
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- P · data can be read
- Integrity
- P · data or configuration can be modified
- Availability
- none
- Attack complexity
- High
- Confidentiality impact
- P
- Integrity impact
- P
- Availability impact
- None
Weakness class (CWE)
CWE-310 · Cryptographic IssuesCVSS vector
AV:N/AC:H/Au:N/C:P/I:P/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.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-01:24.ssh.asc
- marc.info/?l=bugtraq&m=98158450021686&w=2
- www.ciac.org/ciac/bulletins/l-047.shtml
- www.debian.org/security/2001/dsa-023
- www.debian.org/security/2001/dsa-027
- www.debian.org/security/2001/dsa-086
- www.novell.com/linux/security/advisories/adv004_ssh.html
- www.osvdb.org/2116
- www.securityfocus.com/bid/2344
- exchange.xforce.ibmcloud.com/vulnerabilities/6082
Vendor advisories and official records. Exploit/PoC links are deliberately left out.