CVE-2020-14002
published 2020-06-29CVE-2020-14002: PuTTY 0.68 through 0.73 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to…
PriorityP432medium5.9CVSS 3.1
AVNACHPRNUINSUCHINAN
EPSS
3.15%
86.5th percentile
PuTTY 0.68 through 0.73 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client).
Affected
8 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | putty | < putty 0.74-1 (bookworm) | putty 0.74-1 (bookworm) |
| fedoraproject | fedora | — | — |
| fedoraproject | fedora | — | — |
| putty | putty | >= 0 < 0.74-1 | 0.74-1 |
| putty | putty | >= 0 < 0.74-1 | 0.74-1 |
| putty | putty | >= 0 < 0.74-1 | 0.74-1 |
| putty | putty | >= 0 < 0.74-1 | 0.74-1 |
| putty | putty | 0.68 – 0.73 | — |
CVSS provenance
nvdv3.15.9MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
nvdv2.04.3MEDIUMAV:N/AC:M/Au:N/C:P/I:N/A:N
osv5.9MEDIUM
vendor_debian5.9MEDIUM
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VulDB
PuTTY up to 0.73 Algorithm Negotiation information disclosure
vuldb·2026-05-04·CVSS 5.9
CVE-2020-14002 [MEDIUM] PuTTY up to 0.73 Algorithm Negotiation information disclosure
A vulnerability classified as problematic has been found in PuTTY up to 0.73. This affects an unknown function of the component Algorithm Negotiation. This manipulation causes information disclosure.
The identification of this vulnerability is CVE-2020-14002. It is possible to initiate the attack remotely. There is no exploit available.
It is recommended to upgrade the affected component.
GHSA
GHSA-f25w-hjcw-x829: PuTTY 0
ghsa_unreviewed·2022-05-24
CVE-2020-14002 [MEDIUM] CWE-200 GHSA-f25w-hjcw-x829: PuTTY 0
PuTTY 0.68 through 0.73 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client).
OSV
CVE-2020-14002: PuTTY 0
osv·2020-06-29·CVSS 5.9
CVE-2020-14002 [MEDIUM] CVE-2020-14002: PuTTY 0
PuTTY 0.68 through 0.73 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client).
Debian
CVE-2020-14002: putty - PuTTY 0.68 through 0.73 has an Observable Discrepancy leading to an information ...
vendor_debian·2020·CVSS 5.9
CVE-2020-14002 [MEDIUM] CVE-2020-14002: putty - PuTTY 0.68 through 0.73 has an Observable Discrepancy leading to an information ...
PuTTY 0.68 through 0.73 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client).
Scope: local
bookworm: resolved (fixed in 0.74-1)
bullseye: resolved (fixed in 0.74-1)
forky: resolved (fixed in 0.74-1)
sid: resolved (fixed in 0.74-1)
trixie: resolved (fixed in 0.74-1)
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2020-14002 putty: Observable Discrepancy leading to an information leak in the algorithm negotiation
bugzilla·2020-06-30·CVSS 5.9
CVE-2020-14002 [MEDIUM] CVE-2020-14002 putty: Observable Discrepancy leading to an information leak in the algorithm negotiation
CVE-2020-14002 putty: Observable Discrepancy leading to an information leak in the algorithm negotiation
PuTTY 0.68 through 0.73 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client).
References:
https://lists.tartarus.org/pipermail/putty-announce/
https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html
https://www.fzi.de/en/news/news/detail-en/artikel/fsa-2020-2-ausnutzung-eines-informationslecks-fuer-gezielte-mitm-angriffe-auf-ssh-clients/
Discussion:
Created putty tracking bugs for this issue:
Affects: epel-6 [bug 1852417]
Affects: epel-7 [bug 1852418]
Affects: fedora-all [bug 1852416]
---
This
Bugzilla
CVE-2020-14002 putty: Observable Discrepancy leading to an information leak in the algorithm negotiation [fedora-all]
bugzilla·2020-06-30·CVSS 5.9
CVE-2020-14002 [MEDIUM] CVE-2020-14002 putty: Observable Discrepancy leading to an information leak in the algorithm negotiation [fedora-all]
CVE-2020-14002 putty: Observable Discrepancy leading to an information leak in the algorithm negotiation [fedora-all]
This is an automatically created tracking bug! It was created to ensure
that one or more security vulnerabilities are fixed in affected versions
of fedora-all.
For comments that are specific to the vulnerability please use bugs filed
against the "Security Response" product referenced in the "Blocks" field.
For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs
When submitting as an update, use the fedpkg template provided in the next
comment(s). This will include the bug IDs of this tracking bug as well as
the relevant top-level CVE bugs.
Please also mention the CVE IDs being fixed in the RPM changelog and the
fedpkg commit message.
NOTE: this i
Bugzilla
CVE-2020-14002 putty: Observable Discrepancy leading to an information leak in the algorithm negotiation [epel-7]
bugzilla·2020-06-30·CVSS 5.9
CVE-2020-14002 [MEDIUM] CVE-2020-14002 putty: Observable Discrepancy leading to an information leak in the algorithm negotiation [epel-7]
CVE-2020-14002 putty: Observable Discrepancy leading to an information leak in the algorithm negotiation [epel-7]
This is an automatically created tracking bug! It was created to ensure
that one or more security vulnerabilities are fixed in affected versions
of epel-7.
For comments that are specific to the vulnerability please use bugs filed
against the "Security Response" product referenced in the "Blocks" field.
For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs
When submitting as an update, use the fedpkg template provided in the next
comment(s). This will include the bug IDs of this tracking bug as well as
the relevant top-level CVE bugs.
Please also mention the CVE IDs being fixed in the RPM changelog and the
fedpkg commit message.
Discussion:
Use the
Bugzilla
CVE-2020-14002 putty: Observable Discrepancy leading to an information leak in the algorithm negotiation [epel-6]
bugzilla·2020-06-30·CVSS 5.9
CVE-2020-14002 [MEDIUM] CVE-2020-14002 putty: Observable Discrepancy leading to an information leak in the algorithm negotiation [epel-6]
CVE-2020-14002 putty: Observable Discrepancy leading to an information leak in the algorithm negotiation [epel-6]
This is an automatically created tracking bug! It was created to ensure
that one or more security vulnerabilities are fixed in affected versions
of epel-6.
For comments that are specific to the vulnerability please use bugs filed
against the "Security Response" product referenced in the "Blocks" field.
For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs
When submitting as an update, use the fedpkg template provided in the next
comment(s). This will include the bug IDs of this tracking bug as well as
the relevant top-level CVE bugs.
Please also mention the CVE IDs being fixed in the RPM changelog and the
fedpkg commit message.
Discussion:
Use the
https://lists.debian.org/debian-lts-announce/2024/04/msg00016.htmlhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/26TACCSQYYCPWAJYNAUIXJGZ5RGORJZV/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JPV4A77EDCT4BTFO5BE26ZH72BG4E5IJ/https://lists.tartarus.org/pipermail/putty-announce/https://security.netapp.com/advisory/ntap-20200717-0003/https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.htmlhttps://www.fzi.de/en/news/news/detail-en/artikel/fsa-2020-2-ausnutzung-eines-informationslecks-fuer-gezielte-mitm-angriffe-auf-ssh-clients/https://lists.debian.org/debian-lts-announce/2024/04/msg00016.htmlhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/26TACCSQYYCPWAJYNAUIXJGZ5RGORJZV/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JPV4A77EDCT4BTFO5BE26ZH72BG4E5IJ/https://lists.tartarus.org/pipermail/putty-announce/https://security.netapp.com/advisory/ntap-20200717-0003/https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.htmlhttps://www.fzi.de/en/news/news/detail-en/artikel/fsa-2020-2-ausnutzung-eines-informationslecks-fuer-gezielte-mitm-angriffe-auf-ssh-clients/
2020-06-29
Published