Inefficient Algorithmic Complexity in hMailServer
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Progressive Robot Ltd | hMailServer | unaffected |
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No data.
No data.
| Vendor | Product | Versions | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Progressive Robot | Hmailserver |
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Vendor Solution
Upgrade to hMailServer 6.3.6, which builds the canonical header in one pass and chooses the h= fields from an index by name. Until then, lower the maximum message size, which bounds the cost.
No CVSS v4.0
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.428% probability within 30 days)
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Progressive Robot
Progressive Robot hmailserver |
|
| Vendors & Products |
Progressive Robot
Progressive Robot hmailserver |
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Inefficient algorithmic complexity in the inbound DKIM and ARC signature verification of Progressive Robot hMailServer 6.0.0 through 6.3.5 allows a remote unauthenticated attacker to make the mail services unavailable by sending a message. Building the canonical header and choosing the header fields named in a signature's h= tag took time growing with the square of the message's header: the 'simple' canonicalisation prepended each continuation line of a folded field to the lines already gathered, and both canonicalisations searched the gathered fields from the bottom for each h= name and erased the match from the middle of the list. A message whose header holds very many fields, or a field folded over very many lines, with a DKIM-Signature the attacker signs for a domain they control, keeps a worker thread busy for tens of seconds per signature; up to ten signatures are evaluated per message by each of the DKIM and DMARC tests, on the threads that serve delivery and SMTP. | |
| Title | Inefficient Algorithmic Complexity in hMailServer | |
| Weaknesses | CWE-407 | |
| References |
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| Metrics |
cvssV3_1
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