In PuTTY 0.68 through 0.80 before 0.81, biased ECDSA nonce generation allows an attacker to recover a user's NIST P-521 secret key via a quick attack in approximately 60 signatures. This is especially important in a scenario where an adversary is able to read messages signed by PuTTY or Pageant. The required set of signed messages may be publicly readable because they are stored in a public Git service that supports use of SSH for commit signing, and the signatures were made by Pageant through an agent-forwarding mechanism. In other words, an adversary may already have enough signature information to compromise a victim's private key, even if there is no further use of vulnerable PuTTY versions. After a key compromise, an adversary may be able to conduct supply-chain attacks on software maintained in Git. A second, independent scenario is that the adversary is an operator of an SSH server to which the victim authenticates (for remote login or file copy), even though this server is not fully trusted by the victim, and the victim uses the same private key for SSH connections to other services operated by other entities. Here, the rogue server operator (who would otherwise have no way to determine the victim's private key) can derive the victim's private key, and then use it for unauthorized access to those other services. If the other services include Git services, then again it may be possible to conduct supply-chain attacks on software maintained in Git. This also affects, for example, FileZilla before 3.67.0, WinSCP before 6.3.3, TortoiseGit before 2.15.0.1, and TortoiseSVN through 1.14.6.
CVE-2024-31497
“—” beside the score: it is equal to NVD's CVSS score.
This medium-severity CVE scores 5.9 under NVD CVSS v3. EPSS exploit probability: 5.7% (93rd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2024-29377 (ENISA EUVD) · GHSA-6p4c-r453-8743 (GitHub Security Advisories)Source: ENISA EUVD
- Public exploit or proof-of-concept code is available
A fix is available — apply it.
- CVSS v3
- 5.9
- EG Score
- 5.9MEDIUMmedium confidence
- EG Risk
- 43EG Risk 43/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity59% × 45%Impact severity (EG Severity): CVSS 5.9 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation40% × 40%EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 5.7%
- EPSS %ILE
- 93rd
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.9): severity, escalated by confirmed exploitation. This CVE's 5.9 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.9 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
- EG Likelihood
- 5.7% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
April 15, 2024
Last Modified
November 4, 2025
References (32)
- MITRE · CVE Programhttp://www.openwall.com/lists/oss-security/2024/04/15/6Mailing List · Third Party Advisory
- MITRE · CVE Programhttps://bugzilla.redhat.com/show_bug.cgi?id=2275183Issue Tracking
- MITRE · CVE Programhttps://bugzilla.suse.com/show_bug.cgi?id=1222864Issue Tracking
- MITRE · CVE Programhttps://docs.ccv.brown.edu/oscar/connecting-to-oscar/ssh/ssh-agent-forwarding/key-generation-and-agent-forwarding-with-puttyProduct
- MITRE · CVE Programhttps://filezilla-project.org/versions.phpRelease Notes
- MITRE · CVE Programhttps://git.tartarus.org/?h=c193fe9848f50a88a4089aac647fecc31ae96d27&p=simon/putty.gitMailing List · Patch
- MITRE · CVE Programhttps://github.com/advisories/GHSA-6p4c-r453-8743Third Party Advisory
- MITRE · CVE Programhttps://github.com/daedalus/BreakingECDSAwithLLLThird Party Advisory
- MITRE · CVE Programhttps://lists.debian.org/debian-lts-announce/2024/06/msg00014.html
- MITRE · CVE Programhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZS3B37GNGWOOV7QU7B7JFK76U4TOP4V/Mailing List · Third Party Advisory
- MITRE · CVE Programhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MMHILY2K7HQGQRHOC375KRRG2M6625RD/Mailing List · Third Party Advisory
- MITRE · CVE Programhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PUOTQVGC4DISVHQGSPUYGXO6TLDK65LA/Mailing List · Third Party Advisory
- MITRE · CVE Programhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WFDZBV7ZCAZ6AH3VCQ34SSY7L3J7VZXZ/Mailing List · Third Party Advisory
- MITRE · CVE Programhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WMJH7M663BVO3SY6MFAW2FAZWLLXAPRQ/Mailing List · Third Party Advisory
- MITRE · CVE Programhttps://news.ycombinator.com/item?id=40044665Issue Tracking
15 of 32 shown · show the other 17
- MITRE · CVE Programhttps://security-tracker.debian.org/tracker/CVE-2024-31497Third Party Advisory
- MITRE · CVE Programhttps://securityonline.info/cve-2024-31497-critical-putty-vulnerability-exposes-private-keys-immediate-action-required/Press/Media Coverage
- MITRE · CVE Programhttps://tartarus.org/~simon/putty-snapshots/htmldoc/Chapter9.html#pageant-forwardProduct
- MITRE · CVE Programhttps://tortoisegit.orgThird Party Advisory
- MITRE · CVE Programhttps://twitter.com/CCBalert/status/1780229237569470549Press/Media Coverage
- MITRE · CVE Programhttps://twitter.com/lambdafu/status/1779969509522133272Press/Media Coverage
- MITRE · CVE Programhttps://winscp.net/eng/news.phpThird Party Advisory
- MITRE · CVE Programhttps://www.bleepingcomputer.com/news/security/putty-ssh-client-flaw-allows-recovery-of-cryptographic-private-keys/Press/Media Coverage
- MITRE · CVE Programhttps://www.chiark.greenend.org.uk/~sgtatham/putty/changes.htmlRelease Notes · Vendor Advisory
- MITRE · CVE Programhttps://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-p521-bias.htmlVendor Advisory
- MITRE · CVE Programhttps://www.openwall.com/lists/oss-security/2024/04/15/6Mailing List · Third Party Advisory
- MITRE · CVE Programhttps://www.reddit.com/r/sysadmin/comments/1c4wmoj/putty_vulnerability_affecting_v068_to_v08/Press/Media Coverage
- CVE Programhttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IZS3B37GNGWOOV7QU7B7JFK76U4TOP4V/
- CVE Programhttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MMHILY2K7HQGQRHOC375KRRG2M6625RD/
- CVE Programhttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PUOTQVGC4DISVHQGSPUYGXO6TLDK65LA/
- CVE Programhttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WMJH7M663BVO3SY6MFAW2FAZWLLXAPRQ/
- CVE Programhttps://www.vicarius.io/vsociety/posts/understanding-a-critical-vulnerability-in-putty-biased-ecdsa-nonce-generation-revealing-nist-p-521-private-keys-cve-2024-31497
Affected Packages
(13 across 9 ecosystems)
Debian:11(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| filezilla | 3.52.2-3 ... 3.70.6-2 (54 versions) |
| — |
| putty | 0.74-1, 0.74-1+deb11u1, 0.74-1+deb11u1~deb10u1, 0.74-1+deb11u1~deb10u2 |
| — |
Debian:12(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| filezilla | 3.63.0-1 ... 3.71.0-1 (37 versions) |
| — |
| putty | 0.78-2, 0.78-2+deb12u1 |
| — |
Debian:13(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| filezilla | — |
| — |
| putty | — |
| — |
Debian:14(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| filezilla | — |
| — |
| putty | — |
| — |
Alpine:v3.16(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| putty | — |
| — |
Alpine:v3.17(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| putty | — |
| — |
Alpine:v3.18(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| putty | — |
| — |
Alpine:v3.19(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| putty | — |
| — |
Debian:10(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| putty | 0.70-6 ... 0.74-1 (8 versions) |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 7× in last 7d / 38× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 94 of 210 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 6 repeat rows among the latest 100 are merged into the row they repeat. The 116 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-11-02 16:40 UTCEPSS rescoreEPSS 5.7% · 93rd percentile
- 2026-11-01 16:31 UTCEPSS rescoreEPSS 5.7% · 93rd percentile
- 2026-10-31 16:30 UTCEPSS rescoreEPSS 5.7% · 93rd percentile
- 2026-10-30 16:32 UTCEPSS rescoreEPSS 5.7% · 93rd percentile
- 2026-10-29 16:30 UTCEPSS rescoreEPSS 5.7% · 93rd percentile
- 2026-10-28 16:29 UTCEPSS rescoreEPSS 5.7% · 93rd percentile
- 2026-10-27 16:29 UTCEPSS rescoreEPSS 5.7% · 93rd percentile
- 2026-10-26 16:29 UTCEPSS rescoreEPSS 5.7% · 92nd percentile
- 2026-10-25 17:12 UTCEG score recompute
- 2026-10-25 16:30 UTCEPSS rescoreEPSS 5.7% · 92nd percentile
- 2026-10-24 16:30 UTCEPSS rescoreEPSS 5.7% · 93rd percentile
- 2026-10-24 07:31 UTCEG score recompute
- 2026-10-24 07:31 UTCGHSA enrichmentGHSA-6p4c-r453-8743
- 2026-10-23 16:29 UTCEPSS rescoreEPSS 5.7% · 93rd percentile
- 2026-10-22 16:31 UTCEPSS rescoreEPSS 5.7% · 93rd percentile
- 2026-10-21 16:29 UTCEPSS rescoreEPSS 5.8% · 93rd percentile
- 2026-10-20 16:30 UTCEPSS rescoreEPSS 5.8% · 93rd percentile
- 2026-10-19 16:29 UTCEPSS rescoreEPSS 5.8% · 93rd percentile
- 2026-10-18 16:29 UTCEPSS rescoreEPSS 5.8% · 93rd percentile
- 2026-10-18 07:18 UTCEG score recompute
- 2026-10-17 16:30 UTCEPSS rescoreEPSS 5.8% · 93rd percentile
- 2026-10-16 16:36 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-10-15 16:30 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-10-14 16:30 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-10-13 16:30 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
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- 2026-10-12 17:56 UTCEG score recompute
- 2026-10-12 16:31 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-10-11 21:20 UTCEG score recompute
- 2026-10-11 16:13 UTCEG score recompute
- 2026-10-11 13:46 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-10-11 13:16 UTCOSV refresh
- 2026-10-10 19:58 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-10-09 20:05 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-10-08 17:07 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-10-07 23:46 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-10-06 15:15 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-10-05 17:41 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-10-04 23:20 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-10-03 14:24 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-10-01 19:48 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-30 19:43 UTCEG score recompute
- 2026-09-30 15:01 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-29 15:17 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-28 13:49 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-27 13:43 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-26 15:57 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-26 00:23 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-24 14:01 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-23 13:46 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-22 14:46 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-22 01:16 UTCOSV refresh
- 2026-09-20 20:14 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-19 15:40 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-18 19:26 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-16 14:06 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-15 03:08 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-13 16:45 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-12 14:59 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-11 14:51 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-11 09:35 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-08 21:58 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-06 13:46 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-05 15:26 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-04 13:58 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-04 05:05 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-02 22:10 UTCOSV refresh
- 2026-09-02 14:10 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-09-01 13:52 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-30 19:15 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-30 01:20 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-28 21:39 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-27 14:23 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-26 14:44 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-25 13:47 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-24 14:15 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-23 00:17 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-21 23:47 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-20 22:53 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-19 17:02 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-18 13:46 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-16 14:54 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-16 12:09 UTCOSV refresh
- 2026-08-16 02:13 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-15 01:28 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-13 21:59 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-12 13:49 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-11 13:40 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-10 23:58 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-09 13:45 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-08 16:35 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-07 16:25 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-06 13:45 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-05 19:16 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
- 2026-08-04 15:08 UTCEPSS rescoreEPSS 5.8% · 92nd percentile
Publicly available exploits
(2 references)Public exploit code is referenced for this CVE (2 GitHub PoCs). Defenders should treat patch urgency accordingly.
- GitHub PoCHugoBond/CVE-2024-31497-POCPublished May 10, 2024
Proof Of Concept that exploits PuTTy CVE-2024-31497.
Open source ↗ - Open source ↗GitHub PoCedutko/cve-2024-31497Published Apr 17, 2024
Related CVEs(same product + same CWE)
Same product
10 shownDebian:10:putty · Debian:11:filezilla · Alpine:v3.16:putty
Frequently asked(5)
What is CVE-2024-31497?
When was the CVE record for CVE-2024-31497 published?
Is CVE-2024-31497 actively exploited?
What is the CVSS score of CVE-2024-31497?
How do I remediate CVE-2024-31497?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2024-31497
Is Your Infrastructure Affected by CVE-2024-31497?
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