CVE-1999-1053
HighPublic exploitguestbook.pl cleanses user-inserted SSI commands by removing text between "" separators, which allows remote attackers to execute arbitrary commands when guestbook.pl is run on Apache 1.3.9 and possibly other versions, since Apache allows other closing sequences besides "-->".
Published Sep 13, 1999 · Updated Apr 15, 2026
Key Facts
Patch immediately- CVE-1999-1053 is a high-severity vulnerability (CVSS 7.5 v2) affecting HTTP Server (Apache), Matt Wright Guestbook.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 85% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v2
7.5
AV:N/AC:L/Au:N/C:P/I:P/A:P
EPSS (30-day exploit likelihood)
85%
Higher than 99.7% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
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Description
guestbook.pl cleanses user-inserted SSI commands by removing text between "" separators, which allows remote attackers to execute arbitrary commands when guestbook.pl is run on Apache 1.3.9 and possibly other versions, since Apache allows other closing sequences besides "-->".
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| HTTP ServerApache | 1.3.9 | n/a |
| Matt Wright GuestbookMatt Wright | 2.3 | n/a |
Timeline
Publicly disclosed
Sep 13, 1999
Last updated
Apr 15, 2026
References
- advisory19991105 Guestbook.pl, sloppy SSI handling in Apache? (VD#2)
- advisory19990916 Re: Guestbook perl script (error fix)
- patch776
- exploitMSF guestbook_ssi_exec.rb
- exploitExploitDB-16914
FAQ
Common Questions.
guestbook.pl cleanses user-inserted SSI commands by removing text between "" separators, which allows remote attackers to execute arbitrary commands when guestbook.pl is run on Apache 1.3.9 and possibly other versions, since Apache allows other closing sequences besides "-->".
Affected: HTTP Server (Apache) versions 1.3.9; Matt Wright Guestbook versions 2.3. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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