CVE-2003-0543Openssl Vulnerability
Integer overflow in OpenSSL 0.9.6 and 0.9.7 allows remote attackers to cause a denial of service (crash) via an SSL client certificate with certain ASN.1 tag values.
Published Nov 17, 2003 · Updated Aug 4, 2026 · Also known as DEBIAN-CVE-2003-0543, DSA-393, DSA-394
Key Facts
Routine patching- CVE-2003-0543 is a medium-severity vulnerability (CVSS 5.0 v2) affecting Openssl, openssl095 (debian), rootio-openssl.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 27% probability of exploitation in the next 30 days.
- Fixed versions are available, including Openssl 0.9.6c-2.woody.4, Openssl 0.9.7c, openssl095 0.9.5a-6.woody.3.
- Brandefense priority: routine patching, as no exploitation is known and its severity is moderate or low.
Scores
CVSS v2
5.0
AV:N/AC:L/Au:N/C:N/I:N/A:P
EPSS (30-day exploit likelihood)
27%
Higher than 98.0% of all scored CVEs
Exploit maturity
Proof of concept
ATLAS score
36/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Not listed
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Proof of concept
Public exploit code
1
Proof-of-concept links
In-the-wild evidence
0
Reports of active use
Advisories And Exploit References
- advisoryhttps://security-tracker.debian.org/tracker/CVE-2003-0543
- advisoryhttp://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=104893
- advisoryRHSA-2003:290
- advisoryRHSA-2003:291
- advisoryRHSA-2003:292
- advisoryRHSA-2003:293
Description
Integer overflow in OpenSSL 0.9.6 and 0.9.7 allows remote attackers to cause a denial of service (crash) via an SSL client certificate with certain ASN.1 tag values.
Affected Products
16 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| OpensslOpenssl | 0.9.6, 0.9.7 | 0.9.7c |
| openssl095debian | See advisory | 0.9.5a-6.woody.3 |
| rootio-opensslrootio | See advisory | 0.9.7c |
Patched Releases
Openssl
0.9.6c-2.woody.4, 0.9.7c
openssl095
0.9.5a-6.woody.3
rootio-openssl
0.9.7c
Timeline
Publicly disclosed
Nov 17, 2003
Last updated
Aug 4, 2026
References
- advisorysecurity-tracker.debian.org · CVE-2003-0543
- advisorybugzilla.redhat.com · show_bug.cgi
- advisoryRHSA-2003:290
- advisoryRHSA-2003:291
- advisoryRHSA-2003:292
FAQ
Common Questions.
Integer overflow in OpenSSL 0.9.6 and 0.9.7 allows remote attackers to cause a denial of service (crash) via an SSL client certificate with certain ASN.1 tag values.
Affected: Openssl versions 0.9.6, 0.9.7; openssl095 (debian); rootio-openssl. 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.
Fixed versions are available, including Openssl 0.9.6c-2.woody.4, Openssl 0.9.7c, openssl095 0.9.5a-6.woody.3.
Brandefense priority: routine patching, as no exploitation is known and its severity is moderate or low.
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