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Fencer Vulns
high 7.5

CVE-2004-1440 json

Multiple heap-based buffer overflows in the modpow function in PuTTY before 0.55 allow (1) remote attackers to execute arbitrary code via a…

published 2004-12-31 21 y ago modified 2026-06-16 4 mo ago also EUVD-2004-1437

cvss
7.5
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.1%
EPSS 4.1% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

Multiple heap-based buffer overflows in the modpow function in PuTTY before 0.55 allow (1) remote attackers to execute arbitrary code via an SSH2 packet with a base argument that is larger than the mod argument, which causes the modpow function to write memory before the beginning of its buffer, and (2) remote malicious servers to cause a denial of service (client crash) and possibly execute arbitrary code via a large bignum during authentication.

Patch / fix

  • putty Debian 14, Debian 13, Debian 12 0.56-1

debian advisories DEBIAN-CVE-2004-1440

Exploit prediction

4.11% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.