What is CVE-2009-4455?A medium-severity flaw in Adaptive Security Appliance 5500, explained.
CVE-2009-4455 is a medium-severity flaw (CVSS 6.5) in Adaptive Security Appliance 5500 from Cisco, published on 29 December 2009. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 1.3%. If you run an affected version, plan in the vendor’s fix.
Published 29 December 2009. Record last updated 16 June 2026. We keep this page's data up to date.
What is CVE-2009-4455? In plain terms.
It can be attacked from anywhere on the internet with one login. If it works, the attacker can read some data, change some data and slow it down.
The default configuration of Cisco ASA 5500 Series Adaptive Security Appliance (Cisco ASA) 7.0, 7.1, 7.2, 8.0, 8.1, and 8.2 allows portal traffic to access arbitrary backend servers, which might allow remote authenticated users to bypass intended access restrictions and access unauthorized web sites via a crafted URL obfuscated with ROT13 and a certain encoding. NOTE: this issue was originally reported as a vulnerability related to lack of restrictions to URLs listed in the Cisco WebVPN bookmark component, but the vendor states that "The bookmark feature is not a security feature."
What kind of flaw is it?
- UnknownUnknown
How an attack on it works
Read straight from its severity rating, translated out of the shorthand.
- Where an attacker can beAnywhere on the internet
- How hard it is to pull offEasy: no special conditions
- Login needed firstOne login
- What an attacker getsCan read some data, change some data and slow it down
Severity vector: AV:N/AC:L/Au:S/C:P/I:P/A:P
Is CVE-2009-4455 being exploited? Not that we know of.
It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 1.3%. That can change at any time, which is why we keep watching.
Timeline
- Published
- Record last updated
CVE-2009-4455 scores 22. Action: Monitor.
We keep the score of every published flaw up to date as the evidence changes. Four things go into the score, and evidence that criminals are actually using it counts most. In order:
- Evidence it is being exploitedBiggest factor
- How severe it isStrong factor
- How widely exposed it isSmaller factor
- Threat activity around itSmaller factor
85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score.
When CVE-2009-4455 matches software you track, it lands in your list with its score and the reasons behind it.
See your own ranked list →Who is affected by CVE-2009-4455? One product.
The published record lists 1 product from 1 vendor. If you run one of these, check your version, then go to the fix below.
- Hardware
Adaptive Security Appliance 5500
by Cisco
Affected versions7.07.17.28.08.18.2
How do I fix CVE-2009-4455? Four steps.
- Check whether you run itCompare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
- Apply the vendor’s fixInstall the update named in the vendor’s advisory. We’ve put the advisories and patch notes first in the list.
- If you can’t patch todayFollow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
- Keep an eye on itTrack the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.
Does CVE-2009-4455 affect you? We'll keep checking.
Looking flaws up one at a time doesn't scale. Tell us what you run once, and we tell you which flaws matter to you, in what order, and keep watching for new ones.
- Tell us what you runPick your software from a list, or let us work it out from your website.
- We match it to every flawOver 400,000 published flaws, checked against your list.
- Ranked by real-world riskA 0 to 100 score, led by evidence criminals are using it.
- Told as soon as we knowAn alert by email, in the app or by webhook to your own tools.
Free plan, no card needed. Nothing to install.
1 new flaw affects software Acme tracks
The default configuration of Cisco ASA 5500 Series Adaptive Security Appliance (Cisco ASA) 7.0, 7.1, 7.2, 8.0, 8.1, and 8.2 allows portal traffic to access a...
- Matched to
- Adaptive Security Appliance 5500 on Acme's software list
- What to do
- Plan in the vendor’s update
Sent to the alert recipients Acme chose. Also in the app and to Acme's webhook.
CVE-2009-4455 is a medium-severity flaw in Adaptive Security Appliance 5500 from Cisco, published on 29 December 2009. It can be attacked from anywhere on the internet with one login. If it works, the attacker can read some data, change some data and slow it down.
It scores 6.5 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2009-4455 is 22 out of 100, which is Low. Its action is "Monitor". No sign of exploitation and a low forecast. Patch it in your normal update cycle.
It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 1.3%. That can change at any time, which is why we keep watching.
For Adaptive Security Appliance 5500 from Cisco: 7.0, 7.1, 7.2, 8.0, 8.1, 8.2.
Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.