CVE-2019-9894
CVE-2019-9894 is a high-severity vulnerability in Putty with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-320.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- CVSS v2: 6.4
- EPSS exploit prediction: 2% (82nd percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-320
- Affected product: Putty
- Published:
- Last modified:
Description
A remotely triggerable memory overwrite in RSA key exchange in PuTTY before 0.71 can occur before host key verification.
Frequently asked questions
- What is CVE-2019-9894?
- A remotely triggerable memory overwrite in RSA key exchange in PuTTY before 0.71 can occur before host key verification.
- How severe is CVE-2019-9894?
- CVE-2019-9894 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
- Is CVE-2019-9894 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2019-9894?
- CVE-2019-9894 primarily affects Putty. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2019-9894?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2019-9894 published?
- CVE-2019-9894 was published on 2019-03-21 and last updated on 2026-06-17.
References
- http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00004.html
- http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00020.html
- https://lists.debian.org/debian-lts-announce/2019/04/msg00023.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36LWQ3NPFIV7DC7TC4KFPRYRH2OR7SZ2/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LDO3F267P347E6U2IILFCYW7JPTLCCES/
- https://seclists.org/bugtraq/2019/Apr/6
- https://security.netapp.com/advisory/ntap-20190404-0001/
- https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html
- https://www.debian.org/security/2019/dsa-4423
Affected products (7)
- cpe:2.3:a:putty:putty:*:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:28:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:*
- cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
- cpe:2.3:a:netapp:oncommand_unified_manager:-:*:*:*:*:*:*:*
- cpe:2.3:o:opensuse:leap:15.0:*:*:*:*:*:*:*
More vulnerabilities in Putty
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- CVE-2019-17067 — Critical (CVSS 9.8): PuTTY before 0.73 on Windows improperly opens port-forwarding listening sockets, which allows attackers to listen on…
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- CVE-2015-0936 — Critical (CVSS 9.8): Ceragon FibeAir IP-10 have a default SSH public key in the authorized_keys file for the mateidu user, which allows…
- CVE-2015-4166 — Critical (CVSS 9.8): Cloudera Key Trustee Server before 5.4.3 does not store keys synchronously, which might allow attackers to have…
- CVE-2024-36391 — Critical (CVSS 9.1): MileSight DeviceHub - CWE-320: Key Management Errors may allow Authentication Bypass and Man-In-The-Middle Traffic